IP top and bottom seal how-to (?)

I had to change my top and bottom seals on my injection pump last night as they were leaking so badly to cause a no start condition for lack of fuel. I also did the head seal which is more than adequately covered by Jim over at DieselGeek. You will also see below that I followed Jim’s “JB weld method” for this job.
I searched around and could not find any photos of the top and bottom seal on TDI club. I think there were two posts, one by Audi5000 and one by Beowulf that had pics but both were broken. After talking to Jack Bombay I was reassured that nothing would come springing out when doing the top and bottom seals and I decided to Just Go Ahead And Do This.
I took my own pics as I went and hopefully they will help someone out down the road. I’m not ready to call this a “procedure” But I’ll tell you what I did… Hope the veterans will edit, correct and generally comment on the following:
Thanks, Chris E.

TOP and BOTTOM SEAL REPLACEMENT on Bosch VE in my 2002 Golf

Before you begin please read all the posts that follow, they contain additional tips and info from other members!

TOOLS NEEDED:
T30 Torx bit
Sharpie
Scratch awl
MetalNerd tamper socket
Ratchet
Hand vac pump to reprime
Dieselgeek seal kit
Spray cleaner
Rags
Screwdriver
Seal Pick
JB Weld
Wooden dowel
The pump body is a stack of parts with a top and bottom seal.

The replacement is quite straightforward but the trick is that the position of the middle layer determines the quantity adjustment and it is critical to replace it in its exact position. (Failure to do so can result in a runaway engine!)

The prep for this job involves making positioning marks on the pump and Jim at Dieselgeek has come up with the JB weld method.

Throughly clean the entire pump body to ensure crud will not get in when you have it open and to allow JB weld to bond and any other marks you make to be visible. Mix up some JB Weld (I used the 5 minute kind) and apply a couple of blobs to the back two corners, overlapping the middle and bottom layers of the stack. Now walk away and let the JB weld completely harden.
NOTE: several of these photos are upside down looking at the rear of the pump. It is the same view you will have when you stick your head in there and look over the back.

I made more marks with a sharpie and a scratch awl


With the JB weld hardened it is time to pull the top cap and replace the top seal. First the seals:

Use the metalnerd socket to remove the tamper screw and set that aside. Use the T30 bit to remove the remaining bolts of the top cap only. Diesel will spill! Place rags to catch.



Use a pick to lift the pointy tab but don’t scratch inside the actual seal path. Insert the new seal in proper orientation. I used a rag to carefully wipe in an outward direction the lower sealing surface which had some rubber residue there.

Continued below:

Continued

Continued:
At this point I replaced the top cap and loosely tightened only the three T30 bolts.
Remove the fuel return line from the short hardline which comes from the banjo bolt on the top cap. Mine was normal hose clamp - needed flat blade screwdriver.

With the top cap back on use the T30 bit to unscrew the three bolts holding the middle layer.
Now gently tap the middle layer with the wooden dowel to fracture the JB Weld creating jagged edges that can later on be re-mated.

After the Tap,(sorry about the focus!)

Now you can carefully flip over the middle layer, there is still a fuel line and wiring harness attached. Pick out that seal and replace. Keep in mind that if you unintentionally break off any of the fractured JB Weld you won’t have your mating surfaces anymore, be careful!

EDIT BY CORRADO TDI, additional info: at this point the quantity adjuster's "Motor Rod" shown in the last picture has to engage a corresponding hole in the metal ring that floats on the pump's plunger down inside the belly of the pump. When you lower the quantity adjuster to match up the JBWeld fractures you must first make sure the metal ring down inside the pump has the metal ring hole facing 12 Noon (straight up). When you lower the QA you can gently bump the metal ring to make sure the QA motor rod is engaging the metal ring's hole. The QA is an electronically driven motor for sliding the ring back and forth. This controls fuelling. If you fail to engage the ring with the QA as you lower it then you will not be in control of fuelling when you go to start the engine. In all cases that I recall, there will be no damage from failing to rengage the metal ring but the engine will either fail to start or will only idle.
Replace the middle layer, line up the fractures and marks and begin to snug down the three T30 bolts as well as the tamper screw with the Metalnerd socket. Just as you begin to snug down re-check alignment and do final tighten. (I did not get the torque specs but I noticed they were not super tight on disassembly)
Use a hand vac pump to re-rpime attaching it to the return hardline where you removed the rubber fuel return. Prime till you see no bubbles in clear fuel delivery line from fuel filter.
Mine started on the first crank just like normal but idled a bit high at 950 or so and fairly rough. (Had a real zippy feeling on the test drive reminding me of when I first cleaned my intake.) I will get with a buddy with a Vag-com to dial this in. Hammer Mod I guess from here.
Chris E.

UPDATE: I very slightly loosened four bolts and barely tapped toward the passenger side (engine off!) JB weld still visibly "lined up". That got rid of my rough idle. Still waiting to get a vag-com and will put an actual number to it.

CE

Excellent write-up. I will add it to the 'How To' list. Thanks for taking the time to document your procedure.

One thing I might add (suggestion: edit your post, Chris) is that the quantity adjuster's "Motor Rod" shown in the last picture has to engage a corresponding hole in the metal ring that floats on the pump's plunger down inside the belly of the pump. When you lower the quantity adjuster to match up the JBWeld fractures you must first make sure the metal ring down inside the pump has the metal ring hole facing 12 Noon (straight up). When you lower the QA you can gently bump the metal ring to make sure the QA motor rod is engaging the metal ring's hole. The QA is an electronically driven motor for sliding the ring back and forth. This controls fuelling. If you fail to engage the ring with the QA as you lower it then you will not be in control of fuelling when you go to start the engine. In all cases that I recall, there will be no damage from failing to rengage the metal ring but the engine will either fail to start or will only idle.

I would also use the regular JBWeld and let it set up over night. I have not seen the diagonal fracture such as the ones pictured above. A more horizontal fracture would be better for matching back up after the seal is replaced. I know this is difficult to control but the god old regular JBWeld might be a better choice for a horizontal fracture.

Thanks so much for your detailed information regarding this procedure. I followed it precisely and it worked perfectly.

I was hoping on my IP that it was the upper seal but after just changing it I can see the little bubble coming out of the lower seal.

Anyhow, waiting 24 hours till the JB Weld cures and then will tackle it tomorrow.

Well the JB weld did not work well for me. I used the original stuff and left it over night and when I did the tap with the wood dowel it shattered most of the JB Weld right off! Also, using the Sharpie for marking was no good either as the diesel that spilled out washed them all off. The scribe marks are the way to go.

Now, thanks to Greengeeker when I started the car up after doing to lower seal, runaway immediately but I was prepared with the car in 5th gear to stall it. Anyhow, the QA rod was not seated in the collar. Note to those who are doing the lower seal, and as Corrado_tdi pointed out, make sure it seated properly!

Lots of "extras" in Bosch IP seal kit

Hello, I've been trying to do my research before I do this pump reseal, and I can't find anything on all the "extra" seals and crush washers in the Bosch kit I got from dieselgeek. I'm going in right now, and I thought that I'd go ahead and post this with hopes that it will reveal itself to me, or someone will respond by the time I'm in there. Thanks!

There are only three seals that commonly leak on the TDI injection pump. These are the round o-ring head seal and the two quantity adjuster seals. The other seals are nice to have just in case but you won't need most of them ever. The fuel shut off solenoid o-ring can come in handy if you lose it when you replace the head seal.

Is the JB weld necessary? I had to preform the "hammer mod" and had no problem getting the quantity set using the VAG COM for reference. Is this for owners that don't have access to a VAG COM when doing the reseal?

Also, I came across this thread searching for a leaking pump thread. I have an ALH in my Vanagon installed at 50 degrees. It has been trouble free for 10k miles. The Vanagon had been sitting for a couple months in my garage getting the front end serviced. Went to drive it last Sunday and it would not start. It would crank but no start. I had to remove the rear deck to do the usual tests. The pump had lost it's prime. There was fuel laying all over the block and brackets under the pump. I primed the pump with my gravity bleed rig and the injector lines loose. The engine started up fine and drove fine. I cleaned the engine and pump with some simple green and water so that I could determine where the leak was. It has been 2 days since and not a drop of fuel. I found a couple posts where this has happened. I have the reseal kit on order and the Viton O ring, but was just curious. Could priming it and driving it stop the leak? Thank you

Edit: I resealed the pump today. I did the "Head O-ring first and then tackled the cover seals. The pin in the roller was a little confusing when reading, but once I had the top off, I got a better idea. It is difficult to see if you get the pin in the hole. I pulled the top up a few times before I was sure I was hitting the hole. Tightened it up to 13 nm and after bleeding the system got it started. The IQ was a little high at temp, so I shut it down, loosened the bolts and slight tap, retorque and fired it back up. Satisfied with the number now. I did not use the JB weld method as described. I scribed it on the yellow paint mark on the injector side of the pump. I had my lines off already, so it was easy to see. Now that I have the job done, I believe I may have caused the pump to start leaking when I did the hammer mod. The hammer mod directions did not mention the seal may not like this. Well, new seals, bolts torqued, and IQ adjusted to spec verified with the VAG COM. Thank you for the great write up. mark

JB weld is only for those who either don't want to mess with resetting IQ with Vagcom or those who don't have access to Vagcom. If you have Vagcom and are proficient enough to reset IQ then by all means you should use that. Personally, I like the JB weld trick in either case so you start an engine with the correct IQ. You can always fine tune later with the hammer mod.

Jim

Jim, Thank you for the quick reply. I have already received shipping confirmation from Diesel Geek on the seals. Thank you for answering about the JB weld trick. I wanted to be sure, I was not missing a step. Yes ideally the job would be quicker if the quantity was maintained during the reseal. My pump even using all the adaption could not even be adjusted up to 2.0. That is why a resorted to the "hammer mod". Before doing the mod, I set the adaption number back to default and then watched the the software as I dialed in the plate.

What about a leak that comes and goes? I know it is not gone for ever, but is a bit preplexing. The pump must have been almost dry from the leak. Took quite a bit of fuel to reprime it. Thanks again and for supporting our hobby/habit. mark

Mark,

Pumps can leak and then not leak for a while due to temperature changes. It will start leaking again...

corrado tdi said:

Mark,

Pumps can leak and then not leak for a while due to temperature changes. It will start leaking again...

Click to expand...

That makes sense. We have had some crazy temperature swings this winter down here in Florida. I was hopping to pinpoint the leak, but looks like it gets all 3 main seals and then be done with it for a while. thanks again. mark

Fantastic thread and guide. Thanks cerickson!

ATF 'fix'

Yes, thanks for the excellent guide.
I just discovered that my pump is leaking. It was caused by biodiesel that shrunk/damaged the seals (I had heard of that, but had also read that this was no longer a problem on my '03 TDI; uhhhhhh, wrong. No more bio for me, unfortunately).
I told the shop that I cannot afford a new one currently. The very kind and helpful man who runs the shop confided ("don't tell anyone I told you this") there is a 60% chance that the seals can be 'repaired' by filling the fuel filter w/ ATF. He alluded to the Challenger explosion that was caused by cold weather and rings that failed.
I will try this before $1200 on a new fuel pump, or this operation described here.

Uhh, filling the fuel filter with ATF?! Now that's a new one to me. Changing the seals is not that big of a job if you have vag-com, so why would you buy a new pump?

SheeB said:

Uhh, filling the fuel filter with ATF?! Now that's a new one to me. Changing the seals is not that big of a job so why would you buy a new pump?

Click to expand...

Actually, I just put it in the fuel tank. I had misunderstood re the fuel filter.
I would qualify the above procedure as a 'big job'. And it appears that even w/ the markings and JB Weld, a visit to a VAG-COM doctor is required.
This toss of the dice w/ the ATF is a cheap hope/fix. If the leak persists, then it's on to the seal job.
It's amazing how much money this operation saves.
Again; hats off to the man who posted this procedure w/ pix.

ChuckMason said:

Actually, I just put it in the fuel tank. I had misunderstood re the fuel filter.
I would qualify the above procedure as a 'big job'. And it appears that even w/ the markings and JB Weld, a visit to a VAG-COM doctor is required.
This toss of the dice w/ the ATF is a cheap hope/fix. If the leak persists, then it's on to the seal job.
It's amazing how much money this operation saves.
Again; hats off to the man who posted this procedure w/ pix.

Click to expand...

Agreed CM, I did forget about vag-com being required so it could indeed be a task. I would look for a local guru and they can zip the seal replacement off in a jiffy, and would fix the leak(s).

Just finished with the Quanity Adjuster seal replacement. It took me a grand total of 40 minutes, not including the JB Weld drying time. Add anothe 5 minutes to correct a rough idle, and we are done, no fuel leak, more power better idle, and the best part, i saved about $1400.00. The local repair shops and the VW dealer all wanted about $1600.00 to replace (not repair) the fuel pump. I just might start a new business.

Re: Leaking IP,ATF "Fix", and Biodiesel

This is a great thread - thanks to all who have invested quality time in it. Yesterday, my '99.5 Jetta (ALH) failed to start. I replaced the fuel filter, primed the pump, and got fuel leaking from the bottom of the IP. I suspect it's that bottom seal, and I am about to order Dieselgeek's kit, special tool, and the Viton O-Ring. (Wish there was Viton for every ring, but apparently, there's not.) I am gratefully benefiting from everyone's feedback and will post my experience.

CorradoTDI said that the top, lower, and O-ring gaskets are about the only ones a TDI owner will ever need to mess with. I have 177K miles on the car, the last 77k miles (when I bought it) powered by various biodiesel blends (B20 in frigid Truckee winters, B50 spring and fall, B100 summertime). Never had any problems with the fuel, as I am an unusually conscientious user.

Q: Should I just go ahead and replace everything in the pump while I'm in there? Just the top, bottom, and middle seals?

Or, just drop some ATF in the fuel tank!? Please post the results of that crapshoot, Chuckmason! It's also important to note that it's not biodiesel that caused your pump to fail. It's switching from high biodiesel blends to ULSD. This is well documented, especially in the SF Bay area and specifically here:

http://www.biofueloasis.com/html/basics.html#ulsd

Biodiesel swells seals and rubber. I say this based on nearly a decade of biodiesel experience and having never had to mess with an IP until right now. I've racked up over 100,000 miles on three different diesels (Cummins and TDIs), all with as high a biodiesel blend as the weather here in the Sierra Nevadas allows, and so I never used a lower blend of biodiesel than B20 (i.e., 20% bio-D, 80% ULSD) But I did last week. I should say, my wife did. She put 5 gallons ULSD in atop 2 gallons of B20. Biodiesel is heavier than ULSDiesel, so the bio-D sat a couple nights while she traveled, and it was likely burned up first. It was only a couple of nights, but the ULSD got into the pump and shrank the seals and that's very clearly what got me where I am today. I'm rather frustrated, but biodiesel has kept the IP seals in all my vehicles working well. I made the mistake, which is, of course, why I am so frustrated. If I had kept bio in there, I bet I'd be fine.

Q: Just to be sure - is there not a complete Viton kit available for these IPs?

Many thanks,

Or, just drop some ATF in the fuel tank!? Please post the results of that crapshoot, Chuckmason!



Ronnie,

I don't drive that much; still on the first tank of fuel/ATF. (I prefer 2 wheels in L.A. traffic)
So far, I have witnessed the fuel spurting out of the side of the fuel pump on startup only. That is the driver side where a black box is attached. And I don't know if it is only cold startup that causes this 1 oz. +- leak. Maybe when the motor is hot, it does not leak. Will investigate further (when I next use 4-wheel transport).
As bio is now very hard to find here in L.A., I will no longer go back and forth (bio/petrol), like I did previously. I'm sure that was what got me into this mess.
Somewhere (in his bunker) Dick Cheney and his Arab buddies are smiling!

Did you remove the pump? It looks like it's still mounted.

Not my thread

cumminsfromthecold said:

Did you remove the pump? It looks like it's still mounted.

Click to expand...

Any pix in this thread are by he who started it and did all the work. I'm just a guy who has latched on.
But, no, I have not done ANY work yet. Still got my fingers crossed w/ that ATF in the fuel tank.

My personal opinion is to keep the ATF out of the fuel tank and keep in the tranny where it belongs.

See the beginning of this thread.

I just tried to replace the top seal on my wife's 2000 A4, slushbox.

It still leaks.

I used the metalnerd tool, new seal, didn't see any dirt on the faces of the "lid" and the pump, torqued it "tight" - pulling hard on 1/4" socket (basically what was needed to loosen the bolts). Anyone give a suggestion as to what I could have done wrong? I did try again - took it apart to make sure the seal was all the way in the lid, make sure nothing looked odd, and to make sure it was put on as straight as possible.

If I knew a mechanic within 200 miles, I'd take the day to go there. Dripping diesel fuel all the way.