my3sonsracing

Has anyone tried to tear one of the VP44 pumps apart and rebuild it themselves? After all, it is just a pump! I understand the diaphram fails so why not just replace it?
If so, who sells a rebuild kit? anyone know where you can buy the fedex electronics?
Thanks!

yarddog

My understanding is you can't even get parts unless you're certified by Bosch. Part of getting certified is buying a VERY expensive calibration stand. But give it a shot, a VP core is a VP core even if it's in pieces in a box

my3sonsracing

So no idea on the parts....

Bart Timothy

A vp44 rebuild is not a back yard project. It has to be calibrated on a test stand designed for vp44s. Very few injection shops are even able to do it.

nitrousn

Very true. What is said here is true with any injection pump.

my3sonsracing

Thanks for the warning, but I still ain't skeered!
Most guys won't try fixing an automatic trans because of all the "special tools" they say you need. Good ole mechanical aptitude will do it everytime. after all its just nuts and bolts!

I would like to hear from anyone who has actually tried to fix one and anyone with a line on parts for them. My guess that it is the electronics in them rather than the mechanicals that fail.

Thanks!

my3sonsracing

An update if anyone is interested.
I did find parts for this pump - gasket set is $37 and the electronics pak is $374.
There is no magic diaphragm that rips as some people have reported. There are solenoids that control the fuel flow and that is usually the culprit for dead pedal. In addition, the housings simply wear out due to a lubrication problem that Bosch has not fixed. that is why the Lift pump is so important to maintain good positive flow through the injection pump.
There are only a hand full of rebuilders in the US that have spent the $150k to buy the test stand to set up the pump. That is the issue with a do it yourself fix - the electronics have to be programmed on the stand to communicate with the ecm.
I have ordered the gaskets and am going to rip it apart and see what I can do with it. Who knows, maybe I will find a simple fix that the rebuilders don't want us to know about!
I will keep you posted.

P.J

I am as afraid of a VP44 as I would be of an auto trans. "Sepcial" tools or not!
I have a link HERE to a guy that had one fully apart. Too many moving parts in there for this shade tree mechanic. I'm guessing this is why the need for the 150K fixture?
Good luck, I'm curious to hear your results.

my3sonsracing

Is that why u got the 6 speed???
Too many moving parts? that is like a girl too cute to a mechanic!
Thanks for the photos, what was the outcome of this guys experience with the pump?
I will keep you all posted.

P.J

Truthfully, after I found this site a few years ago, I knew that my next truck would be a manual. Autos are complex, too expensive to fix and will leave you sitting on the side of the road with little or no warning. (JMO)

I don't know what this guy was doing with that pump apart, maybe just an exploratory mission or something. I'm not a TDR member, never will be, I just remember someone else getting the wise idea that all the Bosh rebuilders were ripping us off and how he could get the parts for very little money.

The guy I speak of is a member here, I can imagine he didn't get very far. There are super fine/tight tolerances in there, I don't think it is going to work out well for you, but I could be totally wrong too.

my3sonsracing

Well i finally got it tore apart after tracking down the special 5 point torx tamperproof sockets to get the screws out. Not really complicated at all!
I found that the ring and slide valve assembly that actually advances the pump timing was partially siezed. In fact the slide valve would barely move which tells me this was the problem with mine when cold. It is a steel valve in a bronze bore surrounded by aluminum housing - how many different levels of thermal expansion is that! A quick light hone with a brake hone and clean-up has the valve working fine. I dressed up the ring with some 2000 grit paper and some lapping compound and it is free now as well.
I will get the rebuild kit on tuesday and put it back together and report back on my success (hopefully).

Bart Timothy

I think the diaphram you're talking about are the metal diaphrams which separate the high pressure chamber from the low pressure chamber. They do, indeed, crack out, but the new models are holding up much better. The o-ring seals for these are what really takes a beating and this area is probably the largest mechanical failure point

Good luck, but you self-fix is probably not going to work.

linetrash75

Its been a couple of days. Hows the rebuild going? I hope you can get it fixed and working right.

Jed

my3sonsracing

WHOO HOO! Anybody want to drive my "New" truck!!!!

Happy to report that the pump is back together and running like a sewing machine. Much more power and no Dead Pedal! I have only about 10 miles on it so I will keep you advised if anything changes.

See my note above in post #11 that outlines the major problem. I think that is the lack of power and fuel economy issue. It may also be the dead pedal issue as well.

Now, I would not say it went totally without a hitch and the problems were self inflicted. If you are going to do it yur self, I will recommed a few things:
1, do not disturb the bronze ring on the main shaft. It is the reluctor for the timing pickup and controls the timing of the pump. I removed it and had to time it by trial and error.
2, Pay attention to the orientation of the parts as it is possible to get it 180 deg out of sync which I did the first time. There are no marks for alignment of the parts, so mark them upon disassembly to ensure proper re-assembly.
Hardest part of working on it are those darn tamper resistant torx screws and the fact that there are no manuals that I could find.

Parts: Bosch gasket kit (all orings) part# DGK138 from USDiesel in Ft. Worth TX (817) 485-6422 Mr. Brad Glenn. $37.88

If you have above average mechanical aptitude and a want to save $1500, then you can try this yourself. If i get time, I may put together a proceedure or you can e-mail me direct for my opinion and assistance. my3sonsracing@sbcglobal.net

This may not fix a really screwed up pump, but it fixed mine. By the way, this was the original pump in my 2001 3500 with 195,000 miles and it was not worn out.

phil_h

did Mr. Brad Glenn have the brains for it also??