MGBrescuepilot Please Contact Me

Today (Sept 1, 2016) I received the following e-mail (below the row of xxx’s) from “” regarding a post that had just been made to this thread:,2566009,3345754#msg-3345754

For reasons that are unclear to me, the post has been removed, and the account of MGBrescuepilot (aka Jeff R) has been disabled.  I would like very much to contact Jeff R, but have no way to do so, since his account has been disabled.  So, if anyone out there knows who Jeff R is, could you please ask him to shoot me an e-mail at



Revision dated 9/3/2016:

MGBrescuepilot (aka Jeff R) has contacted me, and we have exchanged a few e-mails.  And no, I do not know his actual identity, or where he lives.  It seems that his post, copied below, to the forum is most probably what got him expelled from that forum, although the reasons are not clear, either to him or to me.  He has shared some speculations with me, and I tend to agree with his thoughts, but I guess I’ll not be sharing those speculations here.  I’ll just let you, the reader, make your own.



MGBrescuepilot wrote in Re: SU carburetor rebuild instructions


Did you know Tom Bryant put a link to the negative comments here, “in the interest of fairness” at the beginning of the H4 article?     Looks like he added the link shortly after this  discussion aired on MGE 2 years ago.  I found this discussion searching the MGE archives for info on rebuilding SU’s.  I was also specifically looking for info on the rebushing of throttle shaft.

In this other article on HS-6 rebuilding,  (about 6 paragraphs into it)  he updated in May 2016 that he has gotten a ultra-sonic cleaner to make the carbs he rebuilds pretty.  Before (2014)  he asked that the customers understand the carbs were not going to be cleaned, so if they were not already clean, to do it before sending them to him.  I guess he read the posts here about customers wanting clean,  and he thought about it, and decided it was a good idea to change.  Gotta give him points there. B)-  He discusses centering the jet pretty thoroughly, so if someone wants to roll their eyes about some sentence in that or any other of his discussions, I’m sure they can find something to poke at.  Overall his write-ups on SU’s, in comparison to other similar  write ups, is quite different and more in depth, so I would say better.  Dave Braun says he does not like the write up, and Hap thinks it is a waste of 5 minutes.  Hap does not say why it is a waste, but I imagine it is because he already has his own way of doing it right, and there was nothing for him to learn?  Fair enough, but what has Dave B got to say about what is wrong with the write ups?  I ask because I want to know what not to do, as well as what to do. Is there some bad info there, or just a different way of doing it?

As for the SU bashing, I have read his SU articles and must have missed it.  He gives a lot of tips and pointers, and as he says, he has got more SU’s to rebuild than he can handle, so the informative articles about how he does things are meant for people thinking of rebuilding their own carbs, including some of the best and detailed info on re-bushing with Delrin bushings, and even giving cutting tools sizes for the job.  Like using a 0.358 reamer and 0.366-0.371 delrin bushings, assuming the holes have not already been enlarged, which as he points out, must weaken the casting .  He talks in one about using Teflon O-rings to replace cork glands and bottom jet seal.  He shares info of .090 jet Teflon o-ring sizing, and shows an interesting technique to recess the jet holes to avoid damaging the Teflon.

Don’t know what his prices are now that he (ultrasonic) cleans the carbs, if different,  but price had been including new throttle shafts and delrin bushings with a (“the works’) rebuild of SU pairs for $220, using Teflon and other improved parts he discusses,  and new Joe Curto jets (he also shows you how to figure out if your old jets are any good).  I don’t recall seeing that anywhere else.  And who else uses the Delrin for shaft bushings?  I don’t know, I am asking, does anyone and how much?  Lifetime bushings sounds good to me.

So all I am saying is “a rather harsh review” I think, from MGE members back in 2014, with no real specific reasoning for the negative I can see, except the “cleaning” thing which was a good part of the discussion.  Has anyone use this guy, and can give a review of his work or delrin bushings in general?  thanks-

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Volvo 700/900-Series Fuel Filler Lid & Hinge

This post will be of interest to an extremely limited number of people, but I had a few requests for pictures, so figured I might as well.

In what follows “Before” refers to the condition of my Blue Lid before I “straightened” it.  “After” is after “straightening” that Blue Lid.

Over the past few years, I have heard of several people having problems with new replacement plastic hinges for Volvo 700 and 900 series fuel filler lids not fitting the old lids.  The consensus seemed to be that the problem was that the quality (especially dimensional control) of the new replacement hinges was sub-par.  That is, that the problem was with the hinges, not the lids.  My recent experience would indicate otherwise, that the problem is actually in the lids, not the hinges.

The hinge is Volvo Part Number 1380664-1, and I believe that part number has never been changed since the 700-series was first introduced in the early 1980s.  The lids, however have gone through several revisions, as follows:
1334649-9, supersedes to
3503391-9, supersedes to
3526601-4, supersedes to
9171105-1, supersedes to
All of these lids are clearly intended to fit onto the same hinge.

Here’s a photo of three lids and three hinges:

DSCF1980The Red Lid, at the top left, is from my 1985 745 TurboDiesel.  The hinge that was used to attach it to the car is to its right.  It’s unbroken and still fits the lid.

The Blue Lid, at lower left, is from my 1986 745 TurboDiesel.  It was attached to the car with the broken hinge shown at the center right.  When that hinge broke about a month ago, I purchased a brand-new hinge from Volvo, which did not fit the lid.

That brand-new, Genuine Volvo, hinge is shown at the lower right, just above a brand-new (Green) Lid, Volvo Part Number 30779269-7.   The Red and Blue lids are most likely Volvo P/N 3503391-9, but they could be the earlier P/N 1334649-9; I have no way of knowing which.

The new Genuine Volvo hinge, at the bottom, and the old, unbroken hinge at the top appear to be essentially identical in all their dimensions.  Each fits the Red and the Green lids perfectly.  But, neither fit the Blue Lid when I first tried them in that lid.  I found that quite surprising since the broken hinge (at the center) had fit the Blue Lid perfectly well until the pins broke off the hinge.  Those new hinges, however, fell right out of the lid.  Either the pins on the hinges were too short, or the distance between the “ears” on the lid was too great.

Notice, in the photo above, that the distance across the flats (at the base of the pins) is about 1.975″ for the new, Genuine Volvo, hinge at the bottom, but about 1.990″ for the broken hinge in the middle.  Initially, that difference indicated to me that Volvo had changed the design of its hinges, with new replacement hinges being shorter across the pins.  I believed that the pins on the new replacement hinge were too short, since the old (broken) hinge had fit just fine.  Eventually, however, I took that top hinge off my red car and compared it with the other two, and found that it matched the bottom (new, Genuine Volvo) hinge perfectly.

I now think that the broken hinge, from the blue car, had been larger than normal and that it quite possibly pushed apart the ears on the Blue Lid, such that it no longer fit a standard hinge.  Perhaps someone installed an aftermarket hinge on my blue car, but I don’t know; I’ve only owned the car for a couple of years, and I don’t know much about its history.

Subsequently, on recommendation from people who had used them, I purchased, via the Internet, a supply of Uro brand hinges and tried them in my Blue Lid.  They did not fit, either, although they were a smidgen (0.015″) longer across the pins, and so they came a bit closer to fitting.

The next photo shows a new, Genuine Volvo, hinge on the left, and a new Uro brand hinge on the right:

DSCF1981The above is actually an “After” photo, but I didn’t take a “Before” photo, so this will have to be good enough.  Had I taken a “Before” picture, the hinge on the left (whether Genuine Volvo, or Uro) would not have stayed put in the holes in the lid, but would have slipped right back out, similar to what is shown above.

But, this an “After” photo, and if one were to slip that left hinge into place, it would stay there.

The hinge on the right is Uro brand, and it fits my Red Lid perfectly.  The new Genuine Volvo hinge (at the left) also fits the Red Lid, although not quite as securely because the distance across the hinge pins is about 0.015″ shorter than across the Uro pins.  But it is exactly the same as the old Genuine Volvo hinge that had been holding that lid on my red car until I removed it a couple of weeks ago.

We’ll come back to the pin dimensions shortly, but first, here’s a shot of the Blue and Green lids:

DSCF1982This is a “Before” photo, but I was trying to show the outside dimensions of the ears, not the inside.   Those outsides differ by only about 0.012″, which is not very significant; the new Green Lid is narrower.

Next, another “Before” photo of those same two lids:

DSCF1983Here I was trying to show that the inside dimensions, at the root of the ears, was essentially the same.  Since the photo missed the right dial, you’ll just have to take my word for it that they are essentially the same.

I’m including this photo here because it shows fairly clearly the reinforcement buttresses that were added to the ears on the right lid, which appear to be intended to prevent spread of those ears, such as apparently happened to the Blue Lid on the left.

If you look carefully at the previous photo, you can also see those buttresses, but they’re not as obvious.

Next is an “After” shot of the three lids, comparing the distances between the insides of the “ears”.

DSCF1984The calipers are measuring the distance between the slots through which the pins get inserted.  That measurement is 2.148 for the Red Lid, 2.145 for the Blue Lid, and 2.180, for the Green Lid.  So, theoretically, the new Genuine Volvo hinge should fit the old Red and Blue lids a bit more securely than it fits the new Green Lid.

Again, the above is an “After” photo.  If I had a “Before” shot of the Blue Lid, that distance would be a bit larger.

Now, as promised, we come back to the hinges.  In the next photo, the brand new, Genuine Volvo, hinge is at the top, and the new Uro brand hinge is at the bottom:


The measurement across the pins of the Genuine Volvo hinge is 2.270″.  The Uro hinge measures 2.185″, a difference of 0.015″, so the Uro brand hinge should fit any of the lids a bit more securely, and it does.

So, how did I “straighten” the Blue Lid?  The next shot shows the fixture:

DSCF2010I simply put a C-clamp across the “ears” and pushed them inward, then I set the Blue Lid in a wooden cradle, and used a second C-clamp to bend the center of the lid, between the ears, outward to a more convex shape, as seen from the outside of the vehicle.

Then I put the Blue Lid in my wife’s oven at 200F for about 2-3 hours.  That was about a week ago, and the lid is still holding its “new” shape just fine.  It fits each of the hinges just fine, too.

So, which hinge do I recommend, Uro or Genuine Volvo?  I’m not sure.  The Uro brand hinges are less expensive, but a not a lot less.  And they do fit the Lids a bit more securely.  Assuming they’re made of the same plastic, they should each last equally long.  So, you be the judge.


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Volvo, Volkswagen, Audi Diesel Pierburg Vacuum Pump Rebuild

In Memoriam: JRC, Unity, Maine, December 27, 1949 – October 30, 2014.

This post describes, in general terms, how to rebuild a Pierburg vacuum pump as used on Volvo D24 and D24T engines from 1979 to 1986 in North America and through the 1996 model year in Europe.  The six-cylinder D24 and D24T engines were built by Volkswagen and were also used in the Volkswagen LT truck series.  A similar five-cylinder engine (the D20) also used the same Pierburg vacuum pump and was used in certain Volvo and Audi vehicles.  The four-cylinder Vokswagen Diesel engines of the same era did not use this vacuum pump.

The level of detail presented in this post will not be as great as in most of my earlier posts on other subjects because my intent here is to describe the problems and failure modes and to give a general idea of how to rebuild one of these vacuum pumps, but not to show all the specifics because the machining work involved is beyond the capabilities of most people.

Because I don’t have the necessary machine tools to do this work, I farmed the machine work out to a small local machine shop, which charged me $75.00 per pump for just the machine work.  It is primarily for that reason that I must get a fairly hefty price for these rebuilt vacuum pumps.  In addition to supplying the materials and paying for that machine work, I also had to disassemble and clean the pumps, then reassemble and test the pumps, so I also have a lot of labor invested in this project.

This vacuum pump comes in two basic varieties, as shown in the following photo:

DSCF1900The earlier type pump is shown on the left and the later type is on the right.  Only the earlier type was used on vehicles imported to North America from 1979 to 1986.  The later type is more difficult to rebuild; in fact, I’ve never rebuilt one of them, and I’m not sure that I would be able to if it should be needed.

I currently have a supply of 11 of the early style pump, all rebuilt, tested, and ready for sale at $120.00 each, exchange, plus shipping.  Although I will accept the later type of pump as a core, I prefer not to because they may prove to be impossible for me to rebuild, and I may decide that I will have to charge extra if someone wants to send me a later pump as a core.

I first rebuilt one of these pumps, by the methods described below, on March 30, 2003.  Since then I have rebuilt about 3 dozen of these pumps, and collectively, they have been used for hundreds and hundreds of thousands of miles without any significant problems being reported.  Some of these pumps have been used for well over 100,000 miles.  So, the repair methods and materials have been well tested and are “tried and true.”

The next photo shows how I usually disassemble one of these pumps for repair:

DSCF1901Note the Vise Grips on the back side.  That was necessary for this particular pump because the bolt that holds the piston in has a round head on it.  Some of the pumps use a bolt with a 15 mm hex head, which is a bit easier to deal with.

The next photo shows that bolt, partially removed, as well as the shaft seal:

DSCF1902The shaft seal consists of a plastic ring surrounded by an o-ring.  The seal is held in place by a steel cup-shaped piece that also serves as a base for the spring.  That steel part is not shown in the above photo, although the similar outer washer is partially visible at the top of the photo.

The next photo shows the same seal, but without the shaft:

DSCF1903This seal was in good condition, but many of them are not.  They frequently wear severely, causing the pump to not work well.

The next photo shows the same pump after removal of the seal:

DSCF1904Note the brass (or bronze) bushing that is still in place in the bore.  The plastic seal may be seen lying on the workbench, to the right of the pump.

In the next photo, the brass bushing has been removed:

DSCF1905The shaft (bolt) is lying to the right, with the bushing and o-ring on it, and with the plastic seal lying on the workbench, just above the shaft.  Note that the bore hole for the bolt is stepped so that there is room for the plastic seal and o-ring at the outer end.

The repair procedure involves enlarging the bore hole to accommodate a Delrin bushing, which replaces the brass bushing, as well as the plastic seal and o-ring, with a single component.

Most of the pumps that I’ve disassembled have failed right here at this bushing.  The bushing wore out, which in turn caused the plastic shaft seal to wear out, which resulted in leakage along the shaft and caused the pump to not draw a decent vacuum.

The next photo shows two shafts with their respective bushings, seals, and o-rings:

DSCF1907Notice that in the lower photo, the bushing is worn completely away in one area, as has the shaft seal.  In my experience, this is the most common failure mode for these Pierburg pumps.

Other failure modes are:

  1. Broken valves.  One such broken valve is shown at the lower right of the above photo.  Compare that valve with the one at the top right.  The first few pumps that I repaired had failed with broken valves, and I once thought that was the primary failure mode, but it is not; the shaft seal fails much more frequently.
  2. The rectangular o-rings that seal around the valves often get hard and don’t seal well.  Sometimes they get brittle and break.
  3. I suppose the seal around the large (2.95″, 75mm) piston could fail, but I’ve never seen one that did.

I don’t believe I’ve ever seen any other type of failure, other than caused by misuse or abuse.

In the next photo we see some of the internal components of the pump:

DSCF1908The large rubber seal comes in at least three varieties.  The two siamesed holes for check valves, at the left side of the photo, sometimes don’t have rubber rings all the way around them.  Sometimes one lacks the ring; sometimes the other also lacks the rubber ring.  The smaller of the two rings is used with a 5th check valve, which isn’t always present.  If the larger rubber ring is missing, then an o-ring is used instead.

Also shown in the above photo are:

  1. At top, two plastic spacers.  There is only one of these per pump; I’ve put two in the photo to provide two views of the same item.
  2. At the center, four check valves.  The one at the far right is broken.  This is the first broken check valve that I’ve seen in several years.
  3. At the bottom, two spacers.  Each pump has only one of these.  They come in two varieties; the one at the left includes that aforementioned 5th check valve; the one at the right lacks the check valve.  Each of these two types seems to work well; I’ve never seen any difference in performance between pumps that have the 5th check valve and those that lack it.

In the next photo are all the o-rings, seals, and bushings that I removed from the current batch of 12 vacuum pumps:

DSCF1910 There are twelve of the brass bushings, twelve plastic shaft seals, and 12 shaft seal o-rings. Notice that at the right of the row of 12 bushings are four that are worn out; the eight good bushings are shown end-on; the 4 bad ones are shown lying on their side.  Although it can’t be seen above, the four corresponding plastic shaft seals are also badly worn, and one of them (at far right) is broken, although that isn’t easily seen in the photo because the o-ring is touching the plastic seal at its 4 and 5 o’clock positions.

At the top of the photo are 40 of the rectangular o-rings used for the check valves.  Each pump has at least 3 of these.  Among these 12 pumps, four of them had the fourth check valve o-ring, the rest had the later type gasket, with the integral check valve seal, as described earlier.  We’ll come back to this again a bit later, near the end of this post.

Below we see three repaired vacuum pump bodies, ready for reassembly:

DSCF1939The vacuum pump body at the top has a reddish-brown bushing installed in it.  That bushing is made of Teflon-impregnated Delrin.  When I first started rebuilding these pumps almost 13 years ago, I made some bushings from plain Delrin (white) and some from Teflon-impregnated Delrin to see which would work better.  I could find no difference in performance or longevity, so now I use only the less expensive white Delrin.

The white bushing at the lower right is a new Delrin bushing, and the one at the lower left is a plain (white) Delrin bushing that was originally installed in a 1984 Volvo 760 in January of 2008, and has since been used for about 62500 miles.  The bushing shows a bit of discoloration, but has no detectable wear.  The pump was recently returned to me because the owner thought it had failed.  I reassembled the pump, tested it, and found that it worked just fine.  The owner has since admitted that he didn’t actually check his brake booster for problems before condemning the vacuum pump.  I have returned the pump to its owner; he will put it back in the car and see what happens.  I’m sure the pump is okay.  In fact, it tested the absolute best of any pump I’ve ever tested.  I measured it at 29 inches Hg.

Next we have the same three pumps, with the same bushings, and located in the same positions, but showing the other end of the bushings:

DSCF1940Because of the glare and reflections, the bushing at the top of the photo looks lighter than does the pure Delrin bushing at the lower left, but it is in fact the reddish brown Teflon-impregnated Delrin bushing.

Next is a photo comparing a pump that was just disassembled, at the left, with one that has been re-machined and has a Delrin bushing installed, at the right:

DSCF1945In the pump at the left, you can see the step in the shaft bore hole.  The larger diameter portion (toward the front) is empty space, which doesn’t help with the pump shaft sealing or pump performance.  The Delrin bushing, in the right pump, fills that space and contributes to the shaft sealing and bearing surface area.  It also probably helps to improve pumping performance a bit.

In the next photo we see the back side of the same two pumps:

DSCF1947Notice the stepped hole in the left hand pump.  When re-machining the pump, that step is left in place to ensure that the bushing is securely held in place by the stepped hole, but the inner diameter is enlarged a bit to enable use of a bushing of adequate thickness.

The next photo shows how I re-assemble the pumps, using a gear puller:

DSCF1949Notice the strategically-placed hose clamps at the outer end of the jaws.

DSCF1950Those hose clamps hold the jaws out, away from the bore of the pump, so that I can easily install the 2.95″ diameter piston, shown installed in the next photo:

DSCF1959Also shown in the above photo are the four check valves.  Three of them face outward, and one faces inward.

The next photo shows the same pump with the two aforementioned spacers installed:

DSCF1960Notice that the spacer at the upper right also contains that 5th check valve, which not all pumps have.  As I said earlier, both types of pump seem to work equally well.

The next photo shows the same pump with the gasket installed:

DSCF1963Sorry the lighting isn’t all that good, so things are not easily visible.  So be it.

Next is a close up of the same gasket:

DSCF1964Notice the damage that has been done to the gasket between the 4 and 5 o’clock position due to improper assembly.  Someone else did that.  I reassembled this pump, very carefully, using this gasket, then tested it, and it works well.  But, I have installed this pump on my own vehicle.  It’s not among those that I have for sale.

This check valve, the one that is “backward” from the other three, is the one that sometimes has an o-ring around it and sometimes doesn’t.  The o-ring, if present, is used in place of the rubber ring shown damaged in the photo above.  Gaskets that lack this piece of rubber use a separate o-ring instead.  In pumps that have damaged rings, such as the one shown above, I have occasionally cut away the damaged area and replaced it with an o-ring as is used on the other 3 check valves.

Next is a shot of the above pump being tested on my 1986 Volvo 745:

DSCF1970This particular pump tested at 25″ Hg.  Every one of these dozen pumps tested between 23″ and 29″ Hg.

The 11 pumps that I currently have for sale are shown in the next photo:

DSCF1972The above pumps are not pretty, but in the photo they look a lot dirtier than they actually are.  I make no excuses; they are what they are.  My game is making things work, not making them pretty.  But next time I’ll probably sand blast the pumps while they’re apart.

If you would like to purchase one of these pumps, on an exchange basis, the cost is $120.00 each, plus shipping.  Each pump comes with a 50k mile replacement warranty; if it fails I’ll replace it at no charge.  I do ask for the VIN of the vehicle it’s to be installed on, as well as the odometer reading at the time of installation.  Should the pump be transferred to a different vehicle, the warranty is also transferable; just record and keep the appropriate mileage and VIN information.

My contact information is:

Tom Bryant
32 JBS Way
Wiscasset, Maine 04578


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Review, P-Brake Cables and Shoes, 1998 Volvo V70

I recently purchased some P-Brake parts for a 1998 Volvo V70 from a well-known and reputable vendor.  The Pex 9209756 P-Brake cables and the Pro Parts 271998 P-Brake shoes were so out of spec that I could not install them and had to return them to the vendor.

I have had extremely satisfying dealings with this vendor in the past and consider this particular vendor to be one of “The Good Guys”.  Since I do not feel that the problems I encountered are in any way the fault of the vendor, I will not divulge their name here.

I’m posting this “Review” here solely because it’s the most effective way I can think of to describe the problems to the vendor, whom I have asked to read this post.  When I am satisfied that the problems have been properly addressed, I will remove this post from this blog.

Here’s a shot of the first point of confusion, the packaging for the “Pex 9209756” P-Brake cables:

DSCF1807This would appear to be a Pex part number 4.1073, corresponding to Volvo P/N 35465905 whereas the vendor’s website describes it as Pex 9209756.  I have no explanation for that discrepancy; perhaps the root of the problem is that the vendor sent me the wrong part, but I don’t know that.

Next photo, a shot of the brake handle end of the original Volvo cable (top) and the Pex cable (bottom):

DSCF1808Notice that the Pex cable is about 3/32″ shorter on the brake handle end.  That, in itself, is not a problem, but when combined with the discrepancy in the next photo, it does add to the problem.

Next, the other (wheel) end of the P-Brake cables, original Volvo at the top and Pex at the bottom:

DSCF1809Notice that the Pex cable is about 1/8″ short on this end.  Combine that with the 3/32″ discrepancy on the handle end, and the result is that the inner cable is about 7/32″ too short, either that or the outer sheath is 7/32″ too long.  Either way, the cable is so short that it could not be easily installed, especially in consideration of the problem shown in the next photo:

DSCF1811In the photo above, we see the wheel end of the Pex cable.  It’s sticking out of its socket by about 1/8″.  Try as hard as I might, I could not get that cable shoved in that last 1/8″.

So, add that 1/8″ to the 7/32″ that the cable was short, and you now have a cable that is effectively about 11/32″ (nearly 3/8″) short. I could not install that cable without first removing the hand brake handle from the car’s chassis.  And, even after removing the hand brake handle, it was difficult, and also difficult to stretch the cable into place enough to re-install the handle.

And then, after getting the handle bolted back in place, the cable was so short that I could not pull the handle upward more than about one “click” on its ratchet.  And yes, I did loosen the cable adjustment at the handle as much as possible.  And, BTW, the cable was not yet attached to the shoes at the wheel end, so it was pulled forward as far as it would go.  Still way too short.

So, why couldn’t I slide that cable into its socket at the wheel?  The next few photos show the reasons:

DSCF1812In the photo above, we see that the OD of the o-ring is about 0.845″ for the OEM Volvo cable, but about 0.905″ for the Pex cable, a difference of about 0.060″.  So the o-ring was too big to fit into the socket.

Next is a shot comparing the two o-rings:

DSCF1814The OEM o-ring measures about 0.064″ thick, whereas the Pex o-ring measures about 0.090″, a difference of 0.026″, or roughly .052″ on the diameter.  Hmmmm… remember that the diameter differed by about 0.060″?  Well, the extra 0.008″ is fairly well accounted for by the next photo:


Yep, sure enough, as you can see in the photo above, the diameter of the groove that the o-ring sits in is about 0.008″ bigger for the Pex cable.

In the next photo, the OEM o-ring is at the top and the Pex o-ring is at the bottom.

DSCF1816The size difference is readily apparent.

Another difference between the Volvo and Pex cable is shown in the next photo:

DSCF1818Notice that the innermost diameter of the plastic end is about 0.025″ larger on the Pex cable.  That makes the cable rather difficult to insert into its socket at the wheel.

Onward to the next problem:

DSCF1819Notice in the above photo that the Pex cable is longer between the wheel end on the right and the mounting clamp toward the left of the photo.  Although it’s hard to tell from the photo, that difference is almost exactly 1 inch.

But, it gets worse:

DSCF1821Notice in the photo above that the mounting clamp is not symmetrical; the screw hole is about 1/8″ off center.  Also notice that the clamp on the Pex cable is installed backward, which moves the screw hole about 1/4″ forward of its proper location.  Add that to the 1″ length discrepancy noted above, and you now have a cable that is effectively about 1-1/4″ too long between its two mounting points.  That makes it impossible to properly mount the cable, causing a large bend in the cable and kinking it too much for proper operation.  Totally unacceptable.

Onward to the next problem:

DSCF1830Notice that the crimped ferrule on the OEM cable (top) is round and measures 0.322″, whereas the ferrule on the Pex cable probably started out round but has been crimped to a hexagonal shape.  There are two problems here:

  1. One problem is that the hex does not fit well into the expander, which is designed for a round ferrule.
  2. The bigger problem here is size; the Pex ferrule measures 0.348″, roughly 0.026″ too big to fit into the expander as shown in the next photo:

DSCF1834The round OEM ferrule fits easily into its expander (top).  But the hexagonal Pex ferrule will not fit into its expander without being forced.  Using Vise Grips and screwdrivers, I was able, with difficulty, to force the Pex ferrules into the expanders.  But, then, because I had to return the two cables for the reasons noted herein, I later had to remove those ferrules.  That was extremely difficult and took me about 15 minutes each for the two cables, costing me about 1/2 hour total, just to remove those stupid oversize ferrules from the expanders.

The above comments all pertain to the Pex 9209756 P-Brake cables.  I called the vendor on Friday, 10/16/2015 and requested they send me some replacement cables; this time I ordered Febi 9209756.  The vendor didn’t have any of those in stock, so had to order some for me from their supplier.  The replacement cables arrived here as promised on Tuesday 10/20/2015.  They fit well and were easy to install.  No problems whatsoever with the Febi cables.  But, I did lose more than 4 days of productivity due to my lift being unavailable for other jobs.

And, of course there is the additional expense of paying for shipping on the replacement parts and the cost of shipping the defective parts back.  Overall, it’s a rather aggravating experience.  Then, to add insult to injury, the Pro Parts P-Brake shoes were also defective, which pretty much wasted the rest of day 5.

Now I’m moving on to document what was wrong with the Pro Parts 271998 P-Brake shoes:

DSCF1850Once again, as seen in the above photo, none of the part numbers on the box match the part number I ordered.  I’m not sure why that is.

When I tried to install these Pro Parts P-Brake shoes, I could not get the brand new rotors to slip over the brake shoes.  Not no way, not no how.  And yes, the brake shoes were well-centered, and yes, the expanders (both top and bottom) were loosened as much as possible.

After trying, unsuccessfully, for about a half hour, to install the new rotors, I began to suspect that the problem was too thick a lining on the brake shoes, so I went over to Goodwin’s Volvo and compared them with a brand new OEM set of shoes, as shown in the next photo:

DSCF1852It’s not terribly obvious in the above photo, but the linings are indeed thicker on the Pex shoes (top) than on the OEM Volvo shoes (bottom).  That difference is a bit easier to see in the next photo:


The Volvo shoes are at the top, and the Pex shoes are at the bottom.  The Pex shoe linings are definitely thicker.

After making several measurements of each shoe and averaging the results, I concluded that the Pex shoe linings are about 0.026″ thicker, making their outer diameter about 0.052″ larger than that of the OEM Volvo shoes.  No wonder I couldn’t get the rotors on!

To avoid more lost time, I bought the OEM Volvo shoes and installed them; they went in easily.  I will be returning the Pr0-Parts shoes.

Altogether, I lost more than 5 days of work because of these defective parts (cables and shoes).  And I had to pay extra costs for shipping and for replacement parts. If I were doing this for a living, I’d go broke.


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SU Carburetor Tuning

Today I will discuss tuning of SU carburetors.  Tuning includes mixture adjustment, idle speed adjustment, and synchronization.  It is assumed that your carbs have been properly rebuilt and the jets centered; if not, stop here, because your carbs are likely not tune-able.  Instead, go study one or more of my posts on SU rebuilding, starting with:

The particular carbs in this post are installed in a 1967 Volvo P-1800, owned by a guy in Waterford, Maine whose grandparents bought the car new in Sweden, so it’s a family treasure.  The carbs were rebuilt by the owner, with some assistance from Joe Curto.

Although these particular carbs are HS-6s, on a Volvo P-1800, the procedures described in this post are generally applicable, with only minor variations, to virtually all SU carburetors.

Here’s a photo of the car and its current owner.



And here’s a shot of the carburetors.  These are the nice “3-hole” variety, with threaded holes for screws to hold on the air cleaners, vice the earlier “2-hole” ones, which used bolts and nuts, a lot less convenient.


Here we have a photo of my ancient PSW Tool, which is designed for tuning SU carburetors.  It contains a pair of tubes and wires for balancing the carbs, a jet adjustment wrench, and a (completely useless) “jet centering” tool, which may be seen peeking out of the plastic pocket, just to the left of the jet adjustment wrench.

DSCF1755The jet centering tool is useless because it does not work, nor can I think of any way it could be re-designed to work.  That’s because jets and needles, and jet bearings, are all a bit different, and they really must be centered individually, using the actual parts to ensure proper centering.  Typically, the holes in the jets are a bit off center, so just use your own jet, and your own needle, and center the thing, as shown in my posts on rebuilding.

A tool set similar to my PSW tool is available as item “B” from:

It’s worth having, particularly if you have Type H carbs.  And the wrench, item “C”, is really nice to have.  In my opinion, the “Uni-Syn”, item “A”, is worthless; I can’t think of a less useful tool for adjusting SUs.  And, for reasons noted above, I don’t believe that item “D” (for jet centering) would be of any value, either.

Next is a photo of the PSW tool in use.

DSCF1756But, not everyone has a PSW tool, so I’m going to show you how to make your own synchronization tool from a wire coat hanger.  The homemade one actually works better than the PSW tool for synchronizing and balancing; that’s because the stiffer wires don’t vibrate as much.

Nevertheless, the PSW tool has its uses; the oval tube (at the right in the photo above) being just perfect for adjusting Type H floats, for example.  And that short jet adjustment wrench is really nice to have.

Note that the center-to-center distance between this pair of SUs is about 8-1/2″.



So, cut and bend your coat hanger so it looks something like this.  Notice that the sharp wire ends are bent inward to prevent scratching the dashpot bore holes.  You should read the rest of this post before you make your own synchronizing wires because I’m going to show you what I consider a better design at the end.  But the ones shown in the next photo are the ones I used on this car, so here they are:


The first thing you have to do is to start the car and get it warmed up to normal operating temperature.  If you’re installing carbs that I rebuilt, the jets adjustment nuts will be turned all the way up.  That’s to ensure that the jets are properly centered.

You should turn each jet adjustment nut down about 2-1/2 to 3 turns, then pull your “choke” and start the car.  As the car warms up, push your choke in to lean out the mixture.  Do whatever you have to do to keep the car running at a reasonable speed while it warms up.

Shut the engine off and loosen the linkage between the two carburetors so that each throttle shaft will turn independently.  For Volvo HS-6s, loosen the two nuts that are facing upward, one on each end of the center linkage shaft, as shown in the next photo.  When installing your carbs, make sure those nuts on the linkage face upward; you’ll regret it otherwise.

For other types of SUs, and other makes of cars, the linkage is different, but the principle is the same; you want the two throttle shafts to turn independently, and you don’t want any input from the accelerator pedal.

DSCF1766Also, if necessary, back off the two “fast idle” screws, one on each carburetor, so they don’t contact the “choke” cams and thereby prevent the throttle plates from closing fully.

Now, with the engine still off, put the wires into the carbs as shown in the next photo and align the pointers so they’re both at the same height.

Now, re-start your engine, and adjust the idle screws on the carbs to obtain about 1500 RPM; the exact value isn’t critical, but it should be in the range of 1200-2000 RPM.  You might also check the timing at this point, just to make sure that it isn’t grossly off.  For Volvo B16, B18, and B20 engines, the timing spec is usually given at 1500 RPM, so that’s a good engine speed for checking your timing and for starting to adjust your carburetor mixture.

In the next photo, I’m adjusting the idle screw of one of the carburetors to achieve 1500 rpm while keeping the pointers at the same height to ensure equal flow through each carburetor.  Obviously, you have to adjust both idle screws, alternately, to achieve the goal.

DSCF1760BTW, see that fuel filter, just beneath my right hand?  Get rid of it.  Do not use any fuel filter on your SUs.  Totally unnecessary.  There is nothing that will go through your fuel pump that won’t also go right through your SUs without doing any harm.  Fuel filters on SUs are, quite simply, a breakdown waiting to happen.  You’re better off without them.  And putting a fuel filter upstream of the fuel pump is particularly detrimental, as it can cause vapor lock, starving your engine for fuel.

Well, it’s pretty hard to see in the next photo, but the Tach/Dwell meter shows about 1500 rpm, and the pointers are both at the same height.

DSCF1761Next, adjust each carburetor jet mixture nut while watching the Tach/Dwell meter.  Turn the nuts up and down alternately until you find the position of each nut that maximizes the engine RPM.   It’s not necessary to keep the RPM constant at 1500 RPM.  But you should try to keep it in the range of 1200 to 2000 RPM.

You may have to turn one, or the other, or both, idle screws to maintain equal flow through each carburetor as well as the desired RPM.

I like my analog Tach/Dwell meter much better for adjusting carbs than a digital one.  The analog meter stays relatively steady during adjustment, whereas the digital one I  recently tried jumped around all over the place, making it hard to see the effect of small adjustments of the jets.

DSCF1762Forget about those lift pins under the pistons; they’re useless.  That’s my opinion, anyway.

After maximizing the RPM with one nut, switch to the other and adjust it the same way, then go back to the first one.  Keep at it until you’ve found the point of maximum RPM, where moving either nut, in either direction, causes the RPM to decrease.

You have to wait a few seconds after each adjustment to give the engine time to stabilize at its new RPM; so be patient.



Okay, here we are.  RPM is maximized; pointers are at the same height, and the engine speed is around 1440 RPM, as shown in the next photo:

DSCF1764Note that this analog Tach/Dwell meter has an RPM scale (at the top) for 8 cylinders.  The reading must be doubled for use on a 4-cylinder engine.  So 720 x 2 = 1440 RPM.

Now that you’ve found the point of maximum RPM, you should probably turn each jet adjustment nut downward (i.e., richer) about 1/6 to 1/3 turn (one or two flats).  This seems to help prevent hesitation on acceleration.  So, wait until after you’re able to try your car out on the road, and then decide if you need to richen the mixture by 1 to 2 flats on each carburetor.

Now, adjust the idle speed to about 800 RPM, using the idle screw on each carburetor.  Be sure to keep the pointer wires at the same height to ensure equal flow through each carburetor.

Remember those two linkage rod nuts you loosened a while ago?  Here’s the photo, again:

DSCF1766Well, now it’s time to tighten them.  Unfortunately, I don’t have hands enough to do the job and take pictures too, so I’ll show you two pictures of the process, whereas the job was actually done in one step.

Take a screwdriver and push one of the linkage arms downward until it just touches the bottom of the fork on the end of the throttle shaft, as shown here:

DSCF1767At this point, rather than take a picture as I did, use your other hand to hold a nut driver and tighten the nut while holding the lever arm downward.  See the next photo:

DSCF1768As I said, you really need to hold the lever down at the same time as you’re tightening the nut.  I just don’t have enough hands to do that and take photos too.

Now, do the same operation at the other end of the linkage:

DSCF1769And, of course, you tighten the nut such that the lever arm just touches the bottom of the fork on the end of the throttle shaft.

For Type H carburetors, which have a different center linkage arrangement, just tighten the linkage, being careful to ensure that neither throttle shaft is moved during the process.

At this point, you should grab the throttle linkage at the middle and use it to open both carburetors a bit.  The two pointers should move up simultaneously and at the same rate and height.  If not, recheck your linkage and readjust to ensure that both carburetors open at the same time.

Now it’s time to add oil to the dashpots.  Use Mobil 1, 15W-50:

DSCF1770Nothing else I’ve ever tried works as well.  Nothing.  For more information, refer to:


DSCF1771Fill the dashpots to about 1/4″ below the top of the inner tube.  If you put too much in there, it won’t do any harm, but it will get squeezed out and wasted when you install the dampers.

After installing the dampers, lift each of the two pistons all the way up and use a rag to wipe up any excess oil that gets squeezed out.

Now, before re-installing the air cleaners, go out for a road test, and see how it runs.  You may want to richen the jet adjustment nuts by 1 to 2 flats.

At this time you should also adjust your fast idle screws so they don’t contact the fast idle cams with the “choke” pushed all the way in, but such that they do make contact with the cams as the “choke” cable is pulled out.  Where you leave these screws is pretty much up to your personal preference.

Now it’s time to re-install your air cleaners.

Now, as promised above, here is a photo of my later-design adjustment and synchronization wires:

DSCF1781The bends are at the top of the inner dashpot tubes, rather than at the bottom.  This configuration works a bit better because it holds the top of the wires more steady, with less vibration.  It also makes it less likely that the sharp cut end of a wire might scratch the dashpot tube inside the carburetor.  Also, you can easily cut a little off the bottom end, if you need to, to adjust the height.

Here’s a shot of this later design in use on another P-1800.

DSCF1783Note that the ends of the wires don’t overlap; rather they’re cut so that they almost, but not quite, touch.  That works better; it’s easier to tell if the carburetors pistons are at equal heights.



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Volvo D24T Power Steering Hoses

Today’s post is an unabashed “advertisement.”

Power steering hoses are no longer available for the Volvo 700-series with D24 and D24T engines, and as far as I’ve been able to determine, appropriate crimp-on Banjo-style end fittings are not available in the aftermarket.  So, I’ve made up a few hoses, and they’re available at $100.00 each, plus shipping.  That’s a considerably better price than Volvo’s list price, the last time I bought one, which was $192.59, back on 12/1/2000.

If you’d rather make up your own, here’s how I do it:

DSCF1610The top hose, with the kink in it, is OEM, and has a hole in it.  The bottom hose, except for the Swagelok fitting on the right end, I had made at my local NAPA store with stock crimped-on fittings.  As is written on the tag, the hose cut-length is 15″.  The right crimp-on fitting is 1/4″ FNPT.

The intent is to cut off the 10mm tube on the right end of the OEM hose and install it into the Swagelok fitting, which is Swagelok P/N S-10M0-1-4.   That’s 1/4″ MNPT x 10mm tube, if you want to source some yourself.

If you have an OEM hose with a good tube and banjo fitting, then just cut it off at its maximum possible length, polish the tube end a bit with some fine sandpaper, insert it into the Swagelok fitting, and tighten the nut.  I can sell you a hose assembly without the 10mm tube and Banjo fitting for a bit less than the $100.00 price.

However, those OEM banjo fittings will probably rust through eventually, and if that happens to you, you will need to purchase, or build, a complete assembly.

You’ll need some banjo fittings, such as these:DSCF1612I did a lot of searching for Banjo fittings, and this particular fitting was all that I was able to find available in the USA.  These are plain steel fittings.  I would have preferred to purchase some brass or bronze fittings, or something with a corrosion-resistant finish, but this was all I could get.  They’ll last a long time.

You’ll also need some 10mm od steel tubing.  I purchased mine from  It comes in two wall thicknesses, 1.0mm:

and 1.5mm:

I recommend, and used, the 1.5mm wall thickness variety.

You’ll also need a tube bender for that 10mm OD tube, and you’ll need to silver-solder the tube to the banjo fittings, and at the proper angle, as seen in the next photo.

DSCF1638Assemble the Swagelok fitting into the hose with some Teflon pipe thread sealant.

Notice that the Swagelok fitting comes with a 2-part ferrule.  This is what makes the Swagelok fitting so superior to commonly-available ferrule (compession) fittings.  The two-piece design causes the smaller ferrule to bite securely into the tube, making for an extremely reliable joint.

Swagelok fittings are so reliable, in fact, that they are the only type of compression fitting approved for use on US Naval vessels.  I played a small part in getting those tested and approved a few years ago when I worked at BIW.

DSCF1649So, here we are, 6 brand-new Volvo 700-series D24T Power Steering hose assemblies all ready to go, at a price of $100.00 each, plus shipping.  I can sell them for a bit less without the Banjo fitting and tube.

These won’t fit the 240-series, but if anyone would like one, and can send me an OEM hose to use as a “go-by”, I can make up a few.

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Volvo D24T (Bosch VE) Injection Pump Re-Seal

Today I’d like to describe how to re-seal a Bosch VE Diesel Injection Pump.  This particular one is of the type used on North American 1983 through 1986 Volvo 700-series (740 or 760) vehicles with D24T (2.4 liter Turbodiesel) engines.  The same type of injection pump remained in use for several more years in other parts of the world.

There is a partial parts list, with part numbers and sources, at the very end of this post.

Here’s a photo of the pump as I received it:

DSCF1061Notice that the owner has removed the front mounting plate and the forward cold start thermostat housing.

Next we have something to watch out for:

DSCF1062Notice that little special screw for the cold start cable?  I found that in the bottom of the shipping box.  This time we got lucky and I found the loose piece; next time we might not be as lucky.  Please make sure that all the small components are securely fastened so they don’t get lost during shipment.

Next is a shot of some things *not* to send:

DSCF1063That humongous mounting bracket, and the drive sprocket, are just excess weight.  Please keep both of them and save the shipping costs.  Both ways.  However, if you feel you must send along the drive sprocket, that’s not terribly heavy, and it does have the advantage of my not having to go find a Woodruff key and a nut for my own use during the re-seal.

Next are a couple shots of the Volvo Special tool for locking the drive sprocket to the mounting bracket:

DSCF1064DSCF1065And here’s a shot of the tool being used:

DSCF1066Next are a couple shots of the Volvo special tool used for removing the drive sprocket:

DSCF1067DSCF1068But, you don’t need that special tool to remove the drive sprocket.  A chisel will do:

DSCF1069Leave the nut a bit loose, give that chisel a whack, and the sprocket will come right off.

DSCF1070Don’t lose the Woodruff key.

The same trick may be used to remove the front camshaft sprocket on D24 and D24T engines:

DSCF1071Just loosen the  screw a bit and give the screwdriver a whack; it’ll pop right off.

Next is a shot of the Volvo special tool for removing Injection Pump input shaft seals:

DSCF1077There are other ways to remove the seal, but the special tool is the best, unless you’re re-sealing the whole pump, in which case it’s easier to pop the seal out with a screwdriver, as will be shown later.

Next we will remove the EGR switch mechanism from the top of the IP:

DSCF1081Make note of where the 8mm hex head screws are located so you can put this switch back in its proper orientation later.  From the marks it’s obvious that this one had been previously disturbed by someone else, before it was sent to me.

Actually, there are plenty of indications on this IP that it had been previously “rebuilt”, most likely by a “professional”, i.e., an authorized Bosch repair facility.  Unfortunately for the owner of this pump, and for me, they didn’t do a particularly good job of re-assembling it.  Mistakes were made, and damage was done, which I had to rectify.

Here’s a shot of the vacuum switch on this EGR mechanism:

DSCF1084As can be seen, someone repaired this valve with a hose clamp, appropriately bent to hold it together.  Looks like a decent job.  I didn’t mess with it.

Next, remove the EGR mounting bracket:

DSCF1086There are two 6mm Allen head screws to remove.  The one shown above is short; the one on the other end, shown below, should be considerably longer.

DSCF1088Unfortunately the above screw was too short, which caused damage to the IP, as will be shown later.

Next, remove the EGR switch drive ears, as shown below:

DSCF1089DSCF1090Next, make note of the position of the “throttle” lever:

DSCF1091Notice the scribe mark on the top of the 6mm throttle shaft.  It is aligned with the most clockwise mark on the “throttle” lever.  This will not always be the case; sometimes it aligns with one of the other scribe marks on the lever.  You must make note of which lines match, and you must make sure that you put it back together in the same position.

Next, remove the 10mm hex nut, the lock washer, the spring, and the “throttle” lever:

DSCF1093DSCF1095DSCF1097Notice that there is a washer between the IP and the “throttle” lever.  Don’t forget to re-install it later.  Also, make note of the position of the spring so you can be sure to re-install it properly.

Next, remove the microswitch that cuts out the EGR at idle:

DSCF1099As you may notice from subsequent photos, I didn’t remove this microswitch until much later in the process.  I should have removed it at this stage.

Next, remove the top cover of the IP:

DSCF1100DSCF1101The two rear screws (above) are easy.

To remove the two forward screws, you will probably need to remove the idle screw and the fast idle screw:

First, the idle screw:


Just slightly loosen the jam nut, then remove the screw without disturbing the position of the nut, so you can put it back as close as possible to its former position.

Now take out the forward, inboard, IP cover screw:


Next, remove the fast idle screw:


Again, try to keep the jam nut in position so you can get this screw re-installed in its proper position.

Lay the two idle screws aside, making sure to keep track of which one goes where.


These two screws have their nuts in just about exactly the same position.  That is not the general case; usually, the nuts will be in greatly different positions.

Now remove the forward, outboard IP cover screw:

DSCF1106Notice the ball drive on the end of the Allen wrench.  That makes removal of the two forward screws a lot easier.

Next, remove the fuel limiter screw:

DSCF1107That’s a 13mm wrench.  Again, try to move the jam nut as little as possible so you can put this screw back as close as possible to its original position.

Here’s a shot of the fuel limiter screw:

DSCF1108Notice the washer and the o-ring.

Now, lift off the top cover:

DSCF1109Push the “throttle” lever downward and out of the cover as you lift it off.

DSCF1110The governor springs will stay behind as you lift the cover off:

DSCF1111Here’s a shot of the under side of the top cover:

DSCF1112And another shot of the governor springs:

DSCF1114Align the notch on the shaft with the slot and slip the governor springs out:

DSCF1115Don’t lose the little washer on the “throttle” shaft.  Sometimes it sticks to the top cover, so take a look there, too.

Next, remove the cold start lever:

DSCF1116But, before you take that 10mm hex nut off, make note of the position of the cold start lever, relative to the sheet metal stop:

DSCF1117There should be just a little clearance between the lever and the sheet metal stop when the lever is rotated (gently) up against the internal mechanism of the IP.

Make note of the position of the spring and pick out the washer from the seal recess:

DSCF1118Next, remove the sheet metal stop:


DSCF1120Those screws that were holding the stop and the aluminum housing in place are both too short, and the threads in the aluminum IP housing are visibly damaged as a result.  More on this later.

Remove the large black o-ring seal:

DSCF1123DSCF1124Next, we remove what my Bosch dealer tells me is the pressure regulator valve:

DSCF1125That special Bosch tool is rather hard to come by.  Later, I will show you how to make a substitute, which, IMO, is even better than the official tool.  You will need this special tool, or a good substitute, if you don’t want to do damage to the pressure regulator valve.  So, buy one, or make one.

Here’s the regulator valve all taken out:

DSCF1127Notice that there are 4 o-rings on it, 3 large ones, and one slightly smaller.

Next, remove the altitude compensation solenoid and the tube that connects it to the pressure regulator valve:

DSCF1128DSCF1129Notice the spring adjustment shim in the aluminum housing.  There are more on the other end of the spring.  Make sure you put them all back in.  And make sure that you have at least one shim on each end of the spring.  Which end you put any additional shims on is not critical; the spring tension will be the same, either way.

Here’s a shot of the spring and shims:

DSCF1134This particular pump had three shims on the inner end and one on the outer end.  The number varies from pump to pump.

Now, remove the cast iron high pressure pump head:

DSCF1135Make sure to loosen the screws uniformly so the head comes off squarely.  It’s easy to break something here, although it’s far more likely to happen during reassembly than during removal.

DSCF1136If you have to do some prying, do it gently:

DSCF1137Here’s what the head looks like:

DSCF1138Unfortunately, the photo is out of focus, but notice the washers and adjustment shims on the pins.

Here’s what the innards of this pump looked like after removal of the head:

DSCF1139Yep, things fell all out of place.  Fortunately, I know where they’re supposed to be; you may not have that advantage, so be careful.

More mis-located components:

DSCF1140Another view:

DSCF1141That roller belongs underneath the cam plate, not above it; it fell way out of position.

A close up of the cam plate:

DSCF1142Don’t lose that little thrust washer.

Digging in a little deeper:

DSCF1143Now we need to stand this pump up on its end, so let’s take a look at how to do that:

DSCF1144The sprocket on the left is from this IP.  The one on the right is from a Rabbit Diesel.

Another view:

DSCF1145That Rabbit Diesel sprocket (on the right) makes a much better, and more stable, stand for working on these pumps.  If you can get your hands on one, do so.

Here’s a shot of the Rabbit “stand” in use:

DSCF1146Before we can go any deeper into this IP, we have to remove those triangular screws near the front.  It takes a special tool:

DSCF1148This is the official Bosch special tool.  Later I’ll show you how to make your own, probably better, one.

Here’s the first screw, partially removed:

DSCF1149And the second one:

DSCF1150Notice that there appears to be no copper washer under the head of either screw.  Copper washers were “standard” from the factory.  At first, I thought there was no washer here at all, but later I discovered that there’s actually an aluminum washer here.  Just another indication that this pump had been previously rebuilt.

I neglected to take a photo of the piece that is held in by those two special triangular screws, so here’s a shot of one from another pump:

DSCF1151And another shot of the other side:

DSCF1152Note that the tag says this piece is bent.  That happened when someone (not me, I think) mis-assembled another pump.    The ball got pushed out of place, and if I recall correctly, the high pressure pump got broken at the same time.  It’s easy to do, so be mighty careful.  I eventually straightened this piece out and have since used it in one of my own pumps.

More disassembly:

DSCF1153Pick out the o-ring:

DSCF1155Loosen the jam nut on the governor shaft:

DSCF1157And remove the governor shaft:

DSCF1159Here are the parts, all laid out:

DSCF1165Notice the o-ring seal, and take note of where all the washers and spacers go.  The exact location of the jam nut on the end of the governor shaft is not critical, but try to get it back somewhere close to where it was.

Next, remove the spring steel clip from the inside of the IP:

DSCF1168That will expose the locking pin:

DSCF1170Pull it out:

DSCF1172Using a pick, pull the pin toward the center of the IP:

DSCF1173And finish moving it with pliers:

DSCF1175DSCF1176Now remove the hydraulic piston for the timing advance:

DSCF1179Push the input shaft and roller carrier forward:

DSCF1180And out of the pump:

DSCF1181A closer view, showing the roller cage and governor drive gear:

DSCF1182Here’s what’s behind that governor drive gear:

DSCF1183If you’re certain that your low pressure pump is working and that the vanes are not stuck, then you don’t need to go any deeper into your pump.  I did go deeper in this case, just to be sure.

DSCF1184If you take any portion of that low pressure pump out, make sure you know which side to the parts go; you don’t want the pump casing to be in there backwards.

Here’s a shot of the governor drive gear:

DSCF1190It’s held in place with a pair of rubber cogs, as shown in the next shot:

DSCF1191These rubber cogs seem to last forever unless someone does something stupid to the pump, so you shouldn’t need to replace them.  Sorry the photo is out of focus.

Using a screwdriver, pop out the input shaft seal:

DSCF1197DSCF1198With the seal out, check the input shaft for wobble:

DSCF1200Reinstall the low pressure pump:

DSCF1202Hold the Woodruff key in place with a bit of assembly grease:

DSCF1203And put the input shaft back in place, along with the roller cage, etc.:

DSCF1206Next, get the pin lined up in the center of the pump casing hole, as shown to the right, below:

DSCF1209Try to keep it there while you install the hydraulic piston for the timing advance:

DSCF1210And push the pin down from the roller cage into the hydraulic piston:

DSCF1211Next, install the locking pin:

DSCF1212And the spring clip:

DSCF1213DSCF1217Install a new o-ring on the governor shaft:

DSCF1223Install the governor shaft and flyweights:

DSCF1227Reinstall this little piece:

DSCF1228Thinking that the copper washers were missing, I found some new ones:

DSCF1232But I soon realized that there were already aluminum washers in place, so I didn’t use these copper ones.

The basic timing setting (#1 injection) for the Volvo D24 pump sprocket is shown next:

DSCF1238Of course the above picture is taken with the Woodruff key in place.

But, this pump is easier to work on using the Rabbit sprocket for support:

DSCF1239Secure it in place using the Woodruff key and the nut:

DSCF1240Of course, with the Rabbit sprocket, #1 injection is with the mark on the sprocket aligned with the governor shaft at the top of the pump, as shown next:

DSCF1241That locates the input shaft at this angle, as seen from the front of the IP:

DSCF1242Put the cam rollers in place:

DSCF1243Next, install the drive cog and the spring:

DSCF1246Next, install the cam plate:

DSCF1247DSCF1249Note that the drive pin points toward 1:00 o’clock, or the #1 injection line.

Put some assembly grease on the end of the high pressure pump piston:

DSCF1253Make note of the notch (at 9:00 in the photo) that must be placed over the drive pin, located at #1 injection, and install that little thrust washer:

DSCF1256Like this:

DSCF1263Notice that the control collar has a chamfered edge toward the right (rear) side and a sharp edge (not shown) at the front.  The hole in the face of the control collar goes toward the rear of the pump.

Here it, all in place:

DSCF1264Put a new o-ring on the cast iron head:

DSCF1269Add some assembly grease to the head:

DSCF1270And insert the springs and pins:

DSCF1273Put assembly grease between the adjustment shims to make sure they don’t fall off.

Tip it upside down and move it gently into place:

DSCF1279Be very careful.  This is where you have the greatest potential for destroying your IP.  That high pressure pump is very easily broken during reassembly.  If it doesn’t feel right, take it apart and try again.

DSCF1281Now install a pair of screws into the head and torque it down uniformly.  If you feel any resistance, you may be in danger of breaking the high pressure pump:

DSCF1285 Be very, very, careful.

Now, remove the manual shutoff lever:

DSCF1286But before you remove that nut, make sure you know exactly what orientation to put it back together:

DSCF1287Getting this back together in the right position is critical.  If it’s not right, you will not be able to re-install the governor spring mechanism, and you run the risk of bending or even breaking it.  If in doubt during reassembly, rotate that black (inner) piece one notch counterclockwise relative to the outer handle, as seen in the above picture.

Next, remove the washer and the o-ring:

DSCF1291And install a new o-ring:

DSCF1292Reinstall the handle and then remove the flat head screws:

DSCF1295Punch out the dowel pin:

DSCF1296No need to knock the dowel pin all the way out:

DSCF1297You should see a small pin near the center of the next photo.  That has to come out:

DSCF1298But before I show you how to take that pin out, here’s what can happen if you don’t have the proper tools for the job:

DSCF1298-1I made that mistake a couple of years earlier.  Follow my advice, below, and make sure it doesn’t happen to you.

Here’s a shot of that piece we just took out:

DSCF1299This is the point where I actually removed the idle position microswitch I mentioned earlier.  So, here’s a shot of it, but you should take it out earlier and save yourself some grief:


It should be noted that the screw on the left of the photo is too short.  I replaced it with one of proper length during reassembly.

Next, remove the plug, using a 5mm Allen wrench:

DSCF1301 This plug can be extremely difficult to remove.  I’ve had several where the Allen hex stripped out and the plug stayed in place.  You can’t apply heat here because of the rubber parts in the aneroid, so you need a better way.  The next photo shows a ground-down file I made especially for the job:

DSCF1302That file can be used to file flats on the plug to accept a 13mm open-end wrench.  Fortunately, this plug came out fairly easily, as seen in the next photo:

DSCF1306Nevertheless, I did file flats on the plug before re-installing it, for the next time, just in case.  See below for more information.

Next, remove the pin:

DSCF1309See those “screwdriver” slots?  Well, you’d better have the proper “screwdriver” or you risk breaking the housing, as I showed you earlier.  Here’s another shot, just to remind you:

DSCF1310Next is a proper “screwdriver” for this job.  I had a machinist make it for me:

DSCF1312It’s made from a 7/16″ Grade 5 Allen screw, with a 3/8″ hex head on it.

Per commenter “Dan-C” request, machining dimensions for this “screwdriver” are as follows:

1. Nominal diameter of shank: 7/16″ (0.4375″)
2. Overall length, including head: 1.35″
3. Length without head: 0.92″
4. Major diameter of shank after machining (to fit inside threaded hole): 0.425″
5. Minor diameter of shank after machining (to fit inside screw slot): 0.345″
6. Length of minor (0.345″) diameter: 0.15″
7. Width (thickness) of screwdriver tip: 0.078″
8. Length of screwdriver tip: 0.07″

Here’s another view:

DSCF1313The outside of this Allen screw has been burnished just a smidgen so that it will fit inside and pilot on the threads inside the hole for the plug, as shown next:

DSCF1314Now pick out the o-ring:

DSCF1316If this o-ring leaks, you can lose your prime such that your car won’t start, so it’s really important to replace it when re-sealing one of these turbodiesel injection pumps.

Here’s a shot of a special Bosch tool I bought to go beyond removal of this o-ring and take out parts down deeper in the hole:DSCF1317I’ve never had to use it.  You probably won’t need one either.

Here’s what came out of the hole, along with a new (green) o-ring to put back in:

DSCF1320Put the o-ring in and then re-install the “screw”, thusly:

DSCF1324Tighten it down:

DSCF1327Make sure you install the o-ring, then the “screw”, and tighten the screw, and only then, the pin.  If you put the pin in before tightening the screw, it will pinch the od of the o-ring, and it will leak.  BTDT.  Now, put the pin in.

Next, I put the plug back in, tightened it snugly, and marked the bottom position with my file:

DSCF1328Then, I took the plug back out, and filed two flats on it for a 13mm wrench.  First one side:

DSCF1329Then, the other:

DSCF1330Note that I’m using a flat edge to sit the filed side down on to keep it parallel with the top of the vise.

It’s 13.14mm across the flats:

DSCF1332A bit over 13mm, but all my 13mm wrenches fit it just fine.  Tight, and that’s the way I like it:

DSCF1335Next, install one of the flat-head screws:

DSCF1336And drive the dowel pin in until it touches the flat-head screw:

DSCF1337Finish the job with a punch:

DSCF1339And install the second flat-head screw:

DSCF1341Install a new o-ring on the “throttle” shaft:

DSCF1344Next we have a special tool I had made for installing the governor springs and “throttle” shaft:

DSCF1352The special tool is made from a piece of Delrin rod.

Here it is in use:

DSCF1353Remember that manual shutoff lever I cautioned you about earlier?  Well, here it is again, just to the right of that tube of sealant.  If it’s not located at the proper angle, you will not be able to maneuver the governor springs past it as you re-install the top cover of the IP:

DSCF1354So, save yourself a lot of grief, and potential breakage, and get that lever at the proper angle before you start.

New gaskets for the top cover are difficult to come by, so I use anerobic sealant to ensure no leakage.  I tried Hylomar a few times, but the results were not satisfactory.  The sealant I use is the same one that Volvo uses between the two halves of their later “White Block” cylinder heads.  It’s Volvo Part Number 161059-9.

Here it is, applied to the two halves of the IP:

DSCF1356Next, smear it out, nice and smooth, on each half of the split:

DSCF1357Now, drop the top cover on, being careful to maneuver the governor springs past the manual shutoff lever without bending, or breaking, anything:

DSCF1358Notice that the fuel limiter screw is very, very, loose so as not to interfere with reassembly.

Next, screw the cover down:

DSCF1360This is about how much the manual shutoff lever should rotate:

DSCF1365Put a new o-ring on the fuel limiter screw:

DSCF1366And install it:

DSCF1367Don’t forget to tighten the jam nut:

DSCF1368Put new o-rings on the pressure regulator valve:

DSCF1371It takes three of one size and one of the other. First one off, last one back on:

DSCF1373I just finished putting the last one back on.

The cold-start mechanism and its o-rings:

DSCF1382Note the two different lengths of screws in the next picture:

DSCF1384It had two of the short ones in it; it should have had the longer ones.  The short ones did damage to the threads, especially at the upper hole.  I had to repair the threads.

The thread damage is quite visible in the next photo:

DSCF1385First I tried cleaning up the threads with a tap and installing a proper length screw:

DSCF1386DSCF1388But that didn’t work; the longer screw stripped out, also:

DSCF1389So, I had to install a Helicoil:

DSCF1390I drilled it out by hand to minimize the possibility of drilling too deeply:

DSCF1391Then I installed a Helicoil:

DSCF1392In the next photo, notice the installation tab that is yet to be removed, and also notice the damage to the o-ring seat:

DSCF1393Break out the installation tab:

DSCF1395DSCF1396I put in a small dab of epoxy.  I don’t know if it did any good, but it made me feel better:

DSCF1398Installing the cold-start mechanism:

DSCF1399Installing the timing advance hydraulic cylinder cover:

DSCF1410DSCF1411Installing the timing advance hydraulic cylinder spring:

DSCF1401Installing the pressure regulator valve:

DSCF1402DSCF1403Back to the cold-start mechanism:

DSCF1404DSCF1405DSCF1407Make sure there’s the proper amount of clearance between the lever and the sheet metal stop.

Lubricate the input shaft seal before installing it:

DSCF1412Drive it home with a socket:

DSCF1415DSCF1416More mistakes previously made, almost certainly by an authorized Bosch rebuilder:

DSCF1424These screws are too short.  They should have been as shown in the next photo:

DSCF1425I installed the ones at the right of the above photo.

More previous mistakes:

DSCF1426The screw on the left goes into steel and is correct.  The one on the right goes into aluminum and is too short.  It caused damage to the pump housing.

Another shot of the same bracket, and the left screw:

DSCF1427That left screw is okay because it goes into a steel bracket.

But, the right one, well, that damaged the pump housing as shown below:

DSCF1429I had to repair that hole with a Helicoil, also.

Once again, I drilled it out by hand:

DSCF1433Installing the Helicoil:

DSCF1435DSCF1438Knocking out the installation tab with a punch:

DSCF1439Here’s another threaded hole that was pretty well damaged:


I installed a Helicoil in that hole, also. This time, because I needed a tool longer than my “jobbers” bit, I used a 1/4″ reamer to “drill” out the hole:

DSCF1445And with some small sockets and adapters, I was able to tap the hole for a Helicoil:

DSCF1447Installing the Helicoil:

DSCF1448Just enough room, with none to spare.

Next, install the “throttle” lever, making sure to align the marks properly:

DSCF1454Install the EGR switch drive “ears”:

DSCF1455Pay careful attention to corrosion and other marks on the lever to ensure proper orientation of the ears.  Of course, the EGR probably doesn’t work anyway, and there are ways to adjust it in the field, but not many people have the instructions.

Install the bracket:

DSCF1456And the EGR switch:

DSCF1457Use the markings to get that switch right back where it used to be:

DSCF1458In the next photo, the short screw is what was in this IP.  The longer screw is what should have been there:

DSCF1459This hole now has a Helicoil in it because of damage caused by the short screw.

The proper screw length is 16mm:

DSCF1460The short one is only 10mm long.

Now we get to the Cold Start Thermostat.  This pump came to me without one on it, and it went home without one, but for the sake of completeness, I went through the motions and took photos anyway:

DSCF1461The above shows a cold start thermostat and my special tool for R&R.  I made the tool from an 18mm Craftsman impact socket.

Here’s a shot of the thermostat, all removed, showing the o-ring seal:

DSCF1464And here’s a picture of a pair of new thermostats, one from Volvo, the other from Bosch:

DSCF1465Next, my “special tool” for installing the thermostat housing:

DSCF1467Install the long screw in the top screw hole, crank it down, then install the bottom screw:DSCF1470DSCF1472Since this is going back to the owner without a cold start thermostat, or a front mounting plate, I took that stuff back off:

DSCF1480Next, we replace the front o-ring seal, using my special tool that I made from a 24mm impact socket:

DSCF1484The tool was made by grinding away, on three of the sides, with my Dremel tool, just as I will soon show you for the 12mm variety.

The plug, the o-ring, and the tool are shown below:

DSCF1487This is the first, and so far, only IP that I’ve replaced this o-ring on.  I’ve never known one to leak, and it can be easily replaced in the field, without removing the IP from the vehicle, if it ever does leak, so I recommend you leave yours alone.

Next, we go after the o-ring seal on the fuel shutoff solenoid:

DSCF1488DSCF1490DSCF1491This is also the first of these o-rings that I’ve ever replaced, and once again, I recommend that you leave yours alone unless you have a problem with it.

Next, the altitude compensation solenoid:

DSCF1492DSCF1494I’ve also never replaced one of these o-rings before, and I recommend you don’t either.

Next I discuss the screw that holds the rear timing belt cover to the IP mounting bracket:

DSCF1510See that 6mm screw coming in at the top, from the right?  Life is considerably easier, on both D24 and D24T engines, if that screw, or a similar one, comes in from the left, instead.

You need one about 20mm long, as shown next:

DSCF1511And you need a nut, and when you’re done, it’ll look sort of like this:


With this configuration, it’s much easier to remove and re-install that rear timing belt cover.  Try it, you’ll see.

As a reminder, here’s another look at a top cover and its gasket:DSCF1516And here are three gaskets:

DSCF1517The gasket in the middle is an original one from one of these IPs.  The ones on the left and on the right are what come in repair kits these days.  The one on the left will not fit because of the nubs on it.  The one on the right seems flimsy, and I’ve never used one of them, although my Bosch dealer assures me that work just fine.

I have successfully used ones like the one on the left by removing the nubs with a razor blade.

But, being a certified CB, I prefer to use the one in the middle, along with a bit of anerobic sealant to make sure it doesn’t leak.  So far, the results have been great.

Here’s what the flimsy (right) one looks like installed in the top cover:

DSCF1520Notice how it doesn’t fill the space very well.

And next is what the one on the left looks like on the cover:

DSCF1521It will not fit into the grooves unless you shave the nubs off.

Remember those “triangular” screws for which I promised earlier that I’d show you how to make a special tool?  Well, here we go:

DSCF1523I bought a 3/8″ drive 12mm impact socket from NAPA.  Had to special order it.  I later found them in stock at my local Lowes Store.

I ground out three of the sides using my Dremel tool:DSCF1524I used the small, tapered blue stone for this job.  I used that larger stone (in the caliper) to make the 24mm variety I mentioned earlier.

This home-made tool, with a 3/8″ female socket drive, is considerably more convenient than the official Bosch one, which has a 1/2″ male drive, as shown in the next photo:

DSCF1527I also promised to show you how to make a special tool for the pressure regulator valve:

DSCF1531For this, I purchased a special 10mm square female socket via the Internet.  It’s a CTAT-2048, and it fits certain Ford, BMW, and Toyota drain plugs:

DSCF1544Once again, I removed a bit of material using my trusty Dremel tool and the special chainsaw grindstone shown above.  This homemade tool is also considerably easier to use than the official Bosch tool, which has a 1/2″ male square drive, as shown in the photo above.  The tool in the middle of the top row has been hollowed out to fit onto the oblong screw head of the pressure regulator valve, seen just to its right in the top row.

Now, we move on to the inlet and outlet banjo bolt fittings for the IP:

DSCF1551The one on the left is obviously for the outlet.  The unmarked one on the right is for the inlet.  Don’t mix them up.  Bad things happen if you do.

As seen in the next photo, the outlet banjo bolt has a tiny orifice that serves as a restriction to the flow and causes the pressure inside the IP to increase with engine RPM:

DSCF1554You do not want to restrict the inlet flow, and you do want to restrict the outlet flow.

As seen in the next photo, the outlet banjo bolt has a strainer inside it:

DSCF1556The strainer should keep that small orifice from plugging.  We hope.

As seen in the next photo, the IP will almost fiteasily inside a USPS Flat Rate Box:

DSCF1560Unfortunately, the “throttle” lever sticks outside the box, as seen next:

DSCF1561However, if you want to ship me a pump for rebuild, and if you’d like to do it cheaply, you could remove that lever, taking care to note which of the scribe lines must match up, then re-install the lever arm yourself after I ship it back to you.  Your call.

But, make sure you ship me the lever so I can have it to work with.Here’s a partial parts list.  The list is sorted by Description, and there are optional part numbers, and sources, for several of the items.

Part No. Description 240 700 Cost Source
DGK126 Inj Pump Seal Kit, D24 (Shaft Seal too Large) 1 10.65 Bosch
DGK121 Inj Pump Seal Kit, D24T (Shaft Seal too Large) 1 1 16.92 Bosch
1-460-210-306 O-Ring, 2.5mm x 22mm ID, for Inj Pump Cold Start Thermostat 1 1 2.07 Bosch
2-460-210-012 O-Ring, for Inj Pump front end, 2.5mm x 67.56mm od (2.66″ od) 1 1 4.05 Bosch
2-460-223-001 O-Ring, Green, 32mm od, for Inj Pump Cold Start & Timing Adv. 3 3 2.25 Bosch
1-460-210-347 O-Ring, Viton, 1.5mm x 4mm ID (for TD Inj Pump Top Boost Rod) 1 0.63 Bosch
1-460-210-301 O-Ring, Viton, 2.5mm x 10mm ID (for Inj Pump Cold Start Shaft & Shutoff Lever) 2 2 1.98 Bosch
MSC-31959059 O-Ring, Viton, 2.5mm x 10mm ID (for Inj Pump Cold Start Shaft & Shutoff Lever) 2 2 0.63 MSC
1-460-210-349 O-Ring, Viton, 2.5mm x 18mm ID (for Front IP Plug) 1 1 3.21 Bosch
1-460-210-006 O-Ring, Viton, 2.5mm x 9mm ID (for Inj Pump Shutoff Solenoid) 1 1 2.25 Bosch
1-460-225-082 O-Ring, Viton, 2mm x 10mm ID (for Inj Pump Press Reg Vlv) 3 3 2.84 Bosch
MSC-31958937 O-Ring, Viton, 2mm x 10mm ID (for Inj Pump Press Reg Vlv) 3 3 0.76 MSC
MSC-31958887 O-Ring, Viton, 2mm x 5mm ID (for Inj Pump Fuel Adj Screw) 1 1 0.34 MSC
1-460-210-008 O-Ring, Viton, 2mm x 6mm ID (for Inj Pump Throttle Shaft) 1 1 1.98 Bosch
MSC-31958895 O-Ring, Viton, 2mm x 6mm ID (for Inj Pump Throttle Shaft) 1 1 0.44 MSC
1-460-225-081 O-Ring, Viton, 2mm x 8mm ID (for Inj Pump Press Reg Vlv & Governor Shaft) 2 2 0.76 Bosch
MSC-31958911 O-Ring, Viton, 2mm x 8mm ID (for Inj Pump Press Reg Vlv & Governor Shaft) 2 2 0.71 MSC
1-463-412-301 Screw, 4mm Cheesehead (for Inj Pump Cold Start) 1 1 4.46 Bosch
1-460-105-311 Seal Ring, Metal Washer (for TD Inj Pump Top Boost Rod) 1 1.58 Bosch
844178 Seal, Injection Pump Input Shaft 1 1 10.59 Volvo
1-460-283-312 Seal, Injection Pump Input Shaft 1 1 13.77 Bosch
9139507 Thermostat, Cold Start, Inj Pump 1 1 82.17 Volvo
1-467-202-302 Thermostat, Cold Start, Inj Pump 1 1 76.00 Bosch
1-463-123-576 Tie Rod, Inj Pump Cold Start 1 1 14.03 Bosch

Sorry about the poor formatting.  The list is copied from an Excel spreadsheet, and I don’t seem to have any control over the formatting.

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