leaking injection pump

[akal59]

well my pump has started to leak. I replaced the top seal but that didn't fix the problem . so I'm wondering who might be willing to replace the other seals if I remove and ship the pump to them. thx

 

[TonyJetta]

It all depends on your mechanical skills and how clean you can work. Worst case, pull the IP & send to DIS (see trusted mechanics link in my sig)

Here's a thread with good links, scroll down to post #33.

HTH

Tony

 

[aNUT]

It's the head seal. If you opt to replace this seal with the pump installed in the car using Dieselgeek's procedure, I urge you to rotate the engine until the pump is in the middle of an injection stroke. By doing so, you increase the spring tension holding the internal pieces of the pump together and minimize the possibility of dropping rollers, thrust washers, or the plunger shim into your pump and breaking it.

To find when the pump is in the middle of an injection:
Remove the timing plug located in the hydraulic head centered between the 4 deliver valves (where the lines attach) and remove it. It's a 12mm plug.

Remove the plug and find a drill bit slightly smaller than the pin at the end of it.

Next insert the drill bit into the end of the head.
Rotate the engine (better yet, have an assistant do it) and notice how the drill bit is driven out by the end of the plunger.

When the plunger is at it's maximum lift, (~4mm) the return springs are at maximum tension inside the pump. This is the safest time to try to back the head of the pump out and replace the seal.

Good luck.

 

[akal59]

well it's not the pump head seal. I have replaced both the top seal and the o ring on the pump head. still leaks out a white looking switch type device under the pump head . doe's anyone know what this is? doe's it have a o ring behind it? thx for the help

 

[akal59]

it's the solinoid controled valve

the leak is from a valve under the pump head. it has a bad o ring that leaks . posted so others might check this first. it's easier than the pump head o ring.

 

[akal59]

Help !

well I got the 2 T30 torx bolts out but cant remove the solenoid controlled valve .anyone know if there is a connection that needs to be disconnected to remove the valve?thx

 

[RIP TDI]

N108 valve removal - one case

 

[akal59]

thanks

thank you very much for the reply ,this will help the morale .we will continue the battle monday.

 

[ghostone]

Possible picture of leaking valve??

the leak is from a valve under the pump head. it has a bad o ring that leaks . posted so others might check this first. it's easier than the pump head o ring.

Is there any way to get a picture of this leaking valve / location? I think this may be happening on mine and just want to make sure. Thanks

 

[RIP TDI]

The N108 valve is a light grey plastic cylindrical valve with a wire coming out of it directly below the pump head. Its extremely difficult to visually distinguish between a leaking head O-ring and a leaking N108 valve; the leak appears to be coming from the valve in either case. The leak is rarely coming from from the valve, however. Sometimes a head O-ring is replaced but the leak remains, leading to the conclusion that it must be coming from the valve, but the leak is actually still caused by the head O-ring and a faulty replacement procedure proves to be the culprit.

A leaking head O-ring is so common and a leaking N108 is so uncommon, that a head O-ring replacement should be your first course of action.

 

[ghostone]

After Seal replacement - car wont start

It's the head seal. If you opt to replace this seal with the pump installed in the car using Dieselgeek's procedure, I urge you to rotate the engine until the pump is in the middle of an injection stroke. By doing so, you increase the spring tension holding the internal pieces of the pump together and minimize the possibility of dropping rollers, thrust washers, or the plunger shim into your pump and breaking it.

To find when the pump is in the middle of an injection:
Remove the timing plug located in the hydraulic head centered between the 4 deliver valves (where the lines attach) and remove it. It's a 12mm plug.

Remove the plug and find a drill bit slightly smaller than the pin at the end of it.

Next insert the drill bit into the end of the head.
Rotate the engine (better yet, have an assistant do it) and notice how the drill bit is driven out by the end of the plunger.

When the plunger is at it's maximum lift, (~4mm) the return springs are at maximum tension inside the pump. This is the safest time to try to back the head of the pump out and replace the seal.

Good luck.

Hi Everyone... OK, I have a few questions that I hope all your vast knowledge will help me answer.

1. Can the procedure to find max lift be safely done with the fuel cutoff solenoid removed but the solenoid plunger still in place?

2. I completed the o-ring replacement using an o-ring and procedure from Diesel Geek, and I am unable to get the car to start. I tried priming the pump using the procedure of connecting the vacuum pump to the rear portion of the T fitting on the fuel filter. The vacuum pump holds vacuum pressure and I can see very very slow movement of fuel in the clear fuel line, but no fuel arrives at the vacuum canister. Since the vacuum pump holds vacuum, could this be a pinched o-ring or something else?

Thanks in advance for your help

 

[TonyJetta]

I would start with 'whitedog's no start thread', focusing on IP issues. It's a link in my signature.

Tony

 

[matteas]

For what its worth I just went through something similar after replacing the head o-ring on my car. I was very careful and when it still dripped thought it was the n108. I spent several hours reading about the injector pump and decided to redo the head o-ring as a lesser of the two evils. I got the impression that the n108 leak is so rare that I must have screwed up somehow. I redid the head seal procedure with the better quality o-ring and so far no more leaks.

 

[SheeB]

Next insert the drill bit into the end of the head.
Rotate the engine (better yet, have an assistant do it) and notice how the drill bit is driven out by the end of the plunger.

Just for clarification, is the assistant cranking over the engine with the igntion key (sorry if this sounds like a dumb question)?

 

[TonyJetta]

SheeB, yes, that is correct.

Tony

 

[Dodoma]

Because the leak usually starts are high mileage, a practical solution is to fill the leaking joint or plastering it with a layer of J-B Weld compound and let it cure for some hours. This is a low cost solution that should work.

 

[SheeB]

I redid the head seal procedure with the better quality o-ring and so far no more leaks.

I am assuming the first attempt you used the Bosch green head seal? I noticed using Dieselgeek's procedure, it did make mention that only the Viton head seal will likely only work for that procedure will good results.

 

[SheeB]

Because the leak usually starts are high mileage, a practical solution is to fill the leaking joint or plastering it with a layer of J-B Weld compound and let it cure for some hours. This is a low cost solution that should work.

JB weld and injection pumps are a bad idea IMO. The seals are not that expensive, and if your not up to changing them yourself, I am sure a local guru is a very fair with the associated labour costs.

 

[TonyJetta]

dodoma's suggestion is not recommended.

If you have the tools and time to do it right, just do it right! If you don't have the tools or time, but can find a guru near you...Just Do It RIGHT!

Tony

 

[gmenounos]

Is it ok to crank the engine (in order to get the pump in mid-injection position) while the injector lines are removed? (i.e. is the pump going to spray high pressure fuel everywhere?) I had to remove the lines so I could have enough room to get a socket on the timing plug.

Thanks,

- Greg

 

[TonyJetta]

If the pump is full of fuel, you might get some sprayed around the engine, but not much spray, it's an open pipe! More like a squirt or spit.

Tony

 

[Who Knew]

It's the head seal....

When the plunger is at it's maximum lift, (~4mm) the return springs are at maximum tension inside the pump. This is the safest time to try to back the head of the pump out and replace the seal...

Not being privy to the internals of the IP, is the plunger at its maximum lift when the drill bit is farthest out of the hole, or when the drill bit is deepest in the hole?

Thanks,

Who.

 

[Windex]

When the drill bit is furthest out.

 

[dieseljunkie]

When the drill bit is furthest out.

As an extra margin of safety to prevent any possibility of the plunger disk/ washer from falling out of position, you can make a spring loaded bolt that keeps pressure on the plunger.

 

[Who Knew]

As an extra margin of safety to prevent any possibility of the plunger disk/ washer from falling out of position, you can make a spring loaded bolt that keeps pressure on the plunger.

Once the IP is in the right position (drill bit farthest out), seems best to take the drill bit out and put the plug back in before continuing on with the dieselgeek headseal change proceedure, right? No need to leave the plug out for the entire rest of the thing, right?

Aside:
Perhaps a threaded bushing with a co-axial spring loaded shaft that's about the drill's diameter, with the internal fitting length long enough to keep pressure on the plunger, and external length long enough for the user to be able to judge when the plunger is in the right position. Just let it stay there throughout the seal changing procedure. Seems like a potential metalnerd tool.​

 

[Who Knew]

Done!

OK, so based on what I read last weekend, I ordered dieselgeek's head seal, IP seal kit, and metalnerd tool that Saturday. Arrived last week about Wednesday.

I spent a few hours today on the head seal and top/bottom gasket replacement. I didn't bother with the JB weld technique, I just scribed a line near the front/passenger side corner of the IP body where the QA bolts up.

I already had an outboard engine squeeze bulb in-line fuel primer fixed up because she lost prime so bad so often, so getting fuel all the way through to the return went quick.

I cranked it a bit with the injector end of the lines loose and then looked to see they were wet with fuel. Tighten them up and bam, started right up, and idles with the tach in the same place a it used to, so I figure I got the QA back in the right spot, or close enough for jazz...Or, is there some other nuance I'm missing?

Now, it starts up like it used to, no delay, no more cranking until the battery's almost shot, no more fuel leaks, and plus I think it's a bit more peppy.

Finally, if it were me doing the head seal, or if I have to do it again, I'd try to find a couple M6 x 1.00 x 45mm socket head screws to replace the "silver torx screws" mentioned in the dieselgeek procedure. The heads on these screws are shallow and prone to round out (not nearly as bad as a button head allen, but weak just the same). If you wind up fighting a little to get one out, you don't dare put it back in, or you won't ever get it out. On my t30 torx bit, I touched it up on the belt sander and got the tip of it perfectly squared off with the bit, so I could get full contact all the way down inside the screw's head.

Anyway, thanks all you guys for sharing the info and for keeping this place up so I could find it. I just saved a grand at least.

 

[ghostone]

I finished my pump-head gasket replacement last December and now with over 10k miles on the new gasket, all is working great.

One thing that I must enforce with everyone doing this procedure is to make sure to prime the pump completely and use the method of loosening the injectors to purge air from the lines.

This was the part that made my project take longer than expected. I had primed the pump good.. at least that is what I thought, but the car would not start or spray fuel from the loose injector connection.. This made me think I had not done the gasket replacement correctly.

After I fully primed the pump I was able to get fuel from the loose injector connections.

This is a great, inexpensive fix and I thank everyone that provided the details to make this possible.

 

[B100]

Once the IP is in the right position (drill bit farthest out), seems best to take the drill bit out and put the plug back in before continuing on with the dieselgeek headseal change proceedure, right? No need to leave the plug out for the entire rest of the thing, right?

Aside:
Perhaps a threaded bushing with a co-axial spring loaded shaft that's about the drill's diameter, with the internal fitting length long enough to keep pressure on the plunger, and external length long enough for the user to be able to judge when the plunger is in the right position. Just let it stay there throughout the seal changing procedure. Seems like a potential metalnerd tool.​

I left the timing bolt out while replacing the O-ring, but I like what you're suggesting - assuming exerting positive pressure on the plate/plunger would help keep the internals from slipping out.

 

[HugoStiglitz]

It's the head seal. If you opt to replace this seal with the pump installed in the car using Dieselgeek's procedure, I urge you to rotate the engine until the pump is in the middle of an injection stroke. By doing so, you increase the spring tension holding the internal pieces of the pump together and minimize the possibility of dropping rollers, thrust washers, or the plunger shim into your pump and breaking it.

To find when the pump is in the middle of an injection:
Remove the timing plug located in the hydraulic head centered between the 4 deliver valves (where the lines attach) and remove it. It's a 12mm plug.

Remove the plug and find a drill bit slightly smaller than the pin at the end of it.

Next insert the drill bit into the end of the head.
Rotate the engine (better yet, have an assistant do it) and notice how the drill bit is driven out by the end of the plunger.

When the plunger is at it's maximum lift, (~4mm) the return springs are at maximum tension inside the pump. This is the safest time to try to back the head of the pump out and replace the seal.

Good luck.

C

 

[HugoStiglitz]

Like you couldnt just tell us drill bit size? Jeez