injector pump seals?

GlowBugTDI · Oct 30, 2019

Hey fellow TDI enthusiasts,

here's what i got. So my 2001 alh has 235k on her now, and last winter when it was like 15f below zero or colder the injection pump would leak a little from the bottom right side on start up for a few minutes then it would stop or at least i couldn't tell it was leaking. soon as the weather warmed up and summer was here it was fine. Guess what its cold again and it has started leaking shocking i know. looks like its coming from the bottom right side just below the 4 injector lines where the go into the pump. idk if there's a seal down there but it looks like there could be. it's not spraying, but theres a constant drip every 3-5ish seconds. here's my question if not taken care of could my car leave me stranded somwhere? is it ok to just keep running it, or does it have to be fixed? and will it hurt my pump or motor to run like this?

Thanks all,
GlowBugTDI

csstevej · Oct 30, 2019

It will not get better, and if the leak continues it will leak onto the coolant hose and swell that hose leading to a potential leak or break.

Its not a difficult repair to do, get the dieselgeek kit and watch the video, shouldn’t take more than an hour .

Other option is to run some B50 or stronger biodiesel to swell the oring, down side to that is it is a very effective cleaner and could plug your fuel filter and swell other orings on the pump...

csstevej · Oct 30, 2019

It’s probably the large o ring under the pump head, common to leak as it shrinks.
The new Viton seals fix this issue, but you must watch the video on this as you can seriously damage your pump if you don’t pay attention while doing this.
I’ve done a couple , again not difficult but you must be careful.

GlowBugTDI · Oct 30, 2019

ok sounds good, do you think it would be ok till spring? i don't have a lot of time right now and sense it's my first time idk how long itll take me. I am going to college full time and working whenever i can, so unless i send it to a shop i may not be able to do it till at least Christmas break at the soonest...

ill look at it again but i don't actually think it is that seal i could be wrong so ill check tomorrow, but it looks as if its coming from the actual end of the pump. there's like a center bolt and i think it's coming from there, but idk if thats possible. i just know it's leaking because i see it drip from that area, and theres diesel on that rusty cast iron part from about half way down to the bottom.

thank you!

GlowBugTDI · Oct 30, 2019

if it's coming from that o ring (which it very well may be) maybe that's why i couldn't seem to find the exact leaking point.

Mongler98 · Oct 30, 2019

many bad things happen from leaking pumps
wires get crazy brittle, rubber hoses go bad really fast
you cant fix a mechanical problem with a chemical solution.

GlowBugTDI · Oct 31, 2019

ok, thank you. I think ill just try and keep it clean as possible (Put a rag down there or something), and try to fix it during Christmas break. or see if greengeeker is available haven't met him, but i have heard he does really good work.

GlowBugTDI · Oct 31, 2019

oh i did check this morning and it does seem as tho that may be the o ring. as i can't see a definite spot because it's leaking from the bottom of the pump. it is all the way on the right side so that should be the one. in not one of my injection injector line bolt things is leaking and i don't think that's it...

BobnOH · Oct 31, 2019

Consider sending it off to DFIS in Oregon for a rebuild. It will be costly, but will be like new. You might fix it with that one seal, but sounds like you'll be too engaged to futz with it later. If the car is in otherwise good nick, just think of it as a couple car payments.

GlowBugTDI · Oct 31, 2019

Thank you, i like the idea and will consider it, but i have already thrown 1500+ at the car this summer for different parts (almost all drive terrain/suspension) and i know every one says they last 350k+ but i don't really wanna throw more money into it right now. i like to think of it as a car payment tho lol at least im not paying every month, and the car is in pretty good shape for MN i guess. then again now that ive replaced all those parts it'll go another 150k+....

idk i guess ill think about it a bit. Thanks again for the advice!

csstevej · Oct 31, 2019

Like I said,it’s not difficult to do,, just be prudent doing it follow the videos, in about an hour or two you can have it changed. I believe the kit cost about $30.00 ish bucks, it cones with all,the seals hat you will ever have to change......
Personally I wouldn’t pull it off to,send out when it fairly easy to,do. Save yourself about $900.00 bucks and a couple weeks down time.......plus you wil need all the TB tools and VCDS to install a pump.

Mongler98 · Nov 3, 2019

it is really easy to change seals

terrydtdi · Nov 3, 2019

I aggree with Steve, it's not a bad job to do your self if your somewhat mechanically incline. What you can also do is search guru's in your area. I've done several pump reseals for other TDI folks free of charge.

If it's leaking from the 3 point looking plug on the driver side end of the pump you will need a special tri 3 sided socket (I made one out of a 6 point socket).

https://www.dieselgeek.com/products/24mm-tri-socket-for-tdi-center-plug-seal

Try to spray the pump down and determine where the leak is coming from. If it's leaking from where the steel portion of the pump is connected to the aluminum portion of the pump then it's the pump head seal. as Steve said this is the seal you need to pay close attention to if you consider doing it your self. If it is the pump head seal it can eventually leak bad enough where the pump won't be able to create enough vacuum to keep the pump prime and therefore the car won't run.

Runonbeer has 7 greatly detailed videos on youtube on how to do it.

If you purchase the seal kit, and consider doing the job your self you will want to get the first 3 items on this link, being the regular seal kit, the triangular socket for the security bolt on top of the pump, and the kit that has the viton seals for the pump head. The pump head seal in the first kit doesn't stretch like the viton seals do.

https://www.dieselgeek.com/collections/vw-tdi-injection-pump-seal-kits

GlowBugTDI · Nov 3, 2019

terrydtdi said:
I aggree with Steve, it's not a bad job to do your self if your somewhat mechanically incline. What you can also do is search guru's in your area. I've done several pump reseals for other TDI folks free of charge.

If it's leaking from the 3 point looking plug on the driver side end of the pump you will need a special tri 3 sided socket (I made one out of a 6 point socket).

https://www.dieselgeek.com/products/24mm-tri-socket-for-tdi-center-plug-seal

Try to spray the pump down and determine where the leak is coming from. If it's leaking from where the steel portion of the pump is connected to the aluminum portion of the pump then it's the pump head seal. as Steve said this is the seal you need to pay close attention to if you consider doing it your self. If it is the pump head seal it can eventually leak bad enough where the pump won't be able to create enough vacuum to keep the pump prime and therefore the car won't run.

Runonbeer has 7 greatly detailed videos on youtube on how to do it.

If you purchase the seal kit, and consider doing the job your self you will want to get the first 3 items on this link, being the regular seal kit, the triangular socket for the security bolt on top of the pump, and the kit that has the viton seals for the pump head. The pump head seal in the first kit doesn't stretch like the viton seals do.

https://www.dieselgeek.com/collections/vw-tdi-injection-pump-seal-kits

ok thanks, ill most likely do it my self but if it doesn't work there are two guys in the are that i can have do it. ive done quite a bit of mechanical work on my tdi, and other motor toys but i havent touched the fuel system much so this will be a bit new. ill do some reading, and watch a vid or two before i do it and itll be fine. thanks all!!

csstevej · Nov 3, 2019

Like I said it’s fairly easy, and it seems your handy.
Just watch the vids and you will be fine.

GlowBugTDI · Nov 10, 2019

update, so i rechecked and it turns out it is the big bolt type thing on the end of the right side of the pump. In the center of the 4 injector lines is a big nut type thing with a smaller bolt in the center of it. The bigger nut looking thing is the part that is leaking. is there a seal in there? where do i get that seal and how do i change it?
thank you!

terrydtdi · Nov 10, 2019

That should be the three sided plug. You will need to purchase the socket or you can make one out of a 6 point socket (cut three sides out). I think it was a 15/16” I used. There is a video somewhere on YouTube I think on what’s needed to set the pump up to do it. It’s a pretty easy task.

The seal kit from Diesel Geek has that seal in it. You can also purchase the socket from there as well.

GlowBugTDI · Nov 12, 2019

ok that sounds good. thank you!

fatmobile · Nov 14, 2019

Yeah, I think that's an o-ring.

GlowBugTDI · Dec 8, 2019

http://forums.tdiclub.com/showthread.php?t=487219

not my pic or thread!

but in the fist pic that big center bolt is the one that's leaking. I can't find a video where they change this. Can i just unscrew it replace that o ring and be good or is it holding something in?
thanks!

STDOUBT · Dec 8, 2019

"Can i just unscrew it replace that o ring and be good or is it holding something in"
If only it were that simple. Take the time to find a good walk-through. Unless you do it just right
the innards come apart and then it would need to come out and it gets more complicated...

GlowBugTDI · Dec 9, 2019

oh man!! I was really hoping for a simple fix....

just to be sure im not talking about the big o ring between the two blocks of the pump just that center bolt one. it's like an inch across..

KLXD · Dec 9, 2019

You can remove the three sided plug. Nothing will fall out other than fuel.

Just be aware that you will be uncovering the high pressure piston which is very tight in its bore. You don't want any dirt in there. It also pumps the fuel to the injectors which are close tolerance assemblies also.

Scrub the ell out of the area and flush it with cleaner and do it again before removing the plug.

Be aware that the plug is supposed to be a one time use part due to the metal to metal knife edge seal on the end that seals injection pressure. The o-ring only seals case pressure. It has been reused but find the torque on it.

Plan on doing the head seal. If the plug's leaking the other seals prolly won't be far behind.

GlowBugTDI · Dec 9, 2019

KLXD said:
You can remove the three sided plug. Nothing will fall out other than fuel.

Just be aware that you will be uncovering the high pressure piston which is very tight in its bore. You don't want any dirt in there. It also pumps the fuel to the injectors which are close tolerance assemblies also.

Scrub the ell out of the area and flush it with cleaner and do it again before removing the plug.

Be aware that the plug is supposed to be a one time use part due to the metal to metal knife edge seal on the end that seals injection pressure. The o-ring only seals case pressure. It has been reused but find the torque on it.

Plan on doing the head seal. If the plug's leaking the other seals prolly won't be far behind.

ok thanks that is what i was looking for i can do that it shouldn't be hard. once everything else starts leaking i'll have it re sealed.

injector pump seals?

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