Injection pump head seal

I have a customers car here with a leaking pump head seal. How hard is it to reseal the pump head. I have never taken one apart. If I pull the head does the whole pump have to come apart? I dont want to have springs poping out all over the place. Just wondering if its something I sould try inhouse or send the pump out to be resealed. The pump works great just leaks at the head seal(oring).

Also this customer runs offroad fuel red stuff) in the car. He says that is all he ever runs in it.

I found an old post by drivebywire that has a diagram of the pump. I just dont want to pull it apart if its not something I can put back together. Are ther any special tools needed?

Any help or links would be good. Thanks

I found a procedure on dieselgeeks site that tells how to strech the o-ring over the pump head without fully removing the head.
Has anyone done it this way. I would think stretching the o-ring this much would distort the o-ring.

Thanks

It can be done but if you don't do it right you'll screw up the pump. That's why I don't reseal pumps. If you decide to tackle it then have it in WRITING that they are liable if the pump craps out and not you. It's a risk THEY must assume since the seal vs. rebuild cost is their burden not yours.

Thanks Jason have you ever resealed one still on the car. I do realize after reading the procedure that you must not pull the head back to far or it will come apart(springs).

I am the disclaimer king I always cover my ars.

pump head reseal....

yes...it's a little nerve racking....but done carefully and cleanly it can be done with success....the long bolt supplied by diesel geek is not necessary....but some lube on the o'ring and threads is helpfull for not cutting the ring....probably the biggest danger is the plunger thrust washer falling out of place and getting crushed when the engine turns over....I think that bringing one of the pistons to TDCC will help alleviate this possibility in that tension is kept on the springs when the pump head is loosened....I have actually only done one "pump" head reseal...but have successfully done four complete TDI pump reseals....the pumps are very simple mechanically so even if all the "guts" fall out, with a little vaseline to hold all the parts together it can be reassembled with relative ease....but make sure that you tighten the pump head bolts evenly so as not to bind the piston or other internal components....

I've done two so far, first one was really a high pucker factor. Second one went pretty quickly.

As long as your order dieselgeek's kit/tool, and follow his instructions EXACTLY it's not hard.

I do give the customer the same warning as JasonTDI mentions. It's their dime if somethng breaks.........

I did a former WVO car last week. Top, middle, and pump head seals. What a mess! At least the car would start after I was done. It had been sitting for awhile, and not a drop of fuel in the IP.

Thanks guys I am going to give a shot.

I did the diesel geek (in car) procedure a couple months ago without problems.

If you looking at disassembling the pump I believe pump removal is required.

They say in the instructions that the original seal in their kit once stretched does not go back to its original size. Makes it harder to install properly. If you use the viton seal sold seperately this wont happen.

There is a thread here from a month or so ago where something popped on someone while they tighetened the head and their pump internals broke. It sounds like that is not the norm.

If you follow the instructions carefully it seems ok.

FYI, if the head seal is going the QA upper and lower seals probably arent far behind, mine were bad.

sorry to resurrect an old thread.
If the plunger thrust washer falls inside, will the car start & run normally?
thanks in advance for yr views.

kapilamuni said:

sorry to resurrect an old thread.
If the plunger thrust washer falls inside, will the car start & run normally?
thanks in advance for yr views.

Click to expand...

Uh, no... The pump will be destroyed.

Thanks, I'm relieved. May be you can shed some light on my frustrating issue.
My car's timing chains were changed (BMW M51 6 cylinder engined Rangerover P38 not the AUDI A4 ) in Dec 2016 and afterwards engine started and runs okay. But it has hot start issue (the reason to change timing chains) which continues to trouble me. I was told to adjust the static timing of the injection pump(same as VP37) but I can't get the setting of 0.95mm on the dial gauge, even after pushing the pump full towards the engine, the reading is 0.71mm only. The advise I got was that if the chains were set on timing marks then only reason for such reading is the 'plunger washer falling out'.
Appreciate any advise on this.

1854sailor said:

Uh, no... The pump will be destroyed.

Click to expand...

When you say “destroyed,” do you mean that it will still work, but the engine will run rough? Or do you mean that it will crap out completely and not run at all?

With the shim out of place the plunger will bear directly on the cam plate and the piston stroke will be reduced by the thickness of the shim.

Might run away if the spill port isn't uncovered in the position the plunger ends up in.

Someone posted a picture a while back of the damage resulting from starting the car with the thrust washer having fallen fall out. There were quite a few broken bits and pieces IIRC.

I can imagine with that hard little shim bouncing around.

Was there a runaway involved?

KLXD said:

...Was there a runaway involved?

Click to expand...

I don't remember if there was. I'll do a search for the thread.

What Jimbote said is good advice. Also, Runobeer, has a good video that can be very helpful with re-sealing the Pump Head. I recommend it very highly.

Below, the washer/shim is there in the center of the photo.



Below, you can see the shim with Vaseline holding it in place.
The O-ring was "stuck" to the pump head in this case. So, I had to pull the head.



This link will take you to Runobeer's Thread with video (seems there are a total of 7) > http://forums.tdiclub.com/showthread.php?t=287336&highlight=video