LDA leak on a new Giles pump (observations after resealing)

[zuhandenheit]

I want to report my experience, in case it helps someone, and because I think it's interesting.

I bought a used Giles performance pump one year ago. The seller claimed very low miles, and it looked almost unused. It's been great, and I've run it for around 5k miles. A few months ago, I was disappointed to see that it was leaking diesel at the LDA vent. That's something I've never dealt with before, although my previous three pumps have had all sorts of other leaks.

Before I continue, I want to say that, to be clear, I cannot know if what I have seen in this pump is Giles' doing. Of course anything could have happened between the time he built it and my purchase.

I thought maybe he neglected to replace the offending seal, or perhaps it was somehow damaged during  installation.

Today I replaced it, and I found a seal that was obviously new and looked almost perfect, except for extremely small marks on the inside. I grabbed a pin from my spare pump to compare -- the pin in the Giles pump was worn in a very small area, as though it hardly moved. I could just barely catch my fingernail on the wear marks.

I used the other pin, which came from a pump that was not leaking from the LDA port. My guess is that the wear marks destroyed a new sealil.

I don't know and for sure I don't blame Giles. But I will say, if I ever were to go through this process again, I'd make sure the pin is very smooth and polish it if necessary.

[libbydiesel]

It is unlikely that the boost pin has anything to do with the leak.  There is a feeler pin that rides against the boost pin.  Around that feeler pin is an o-ring that seals against case pressure.  It's a pain to change but doable.  Worst part of the process is that the pump lid needs to be removed so you need to deal with the accelerator lever return springs.  Send me your e-mail and I'll send you a pictorial I made that shows the step-by-step process for replacing that o-ring.   

[zuhandenheit]

Yes, I'm sorry - I misspoke: I replaced the o-ring for the feeler pin. (And it had wear that I suspect caused the early failure of the seal.)

I would have liked very much to have your pictures as a guide. But I'd removed the tops of a few pumps, and I tried removing the feeler pin from an old pump as practice.

[Buji88]

It is unlikely that the boost pin has anything to do with the leak.  There is a feeler pin that rides against the boost pin.  Around that feeler pin is an o-ring that seals against case pressure.  It's a pain to change but doable.  Worst part of the process is that the pump lid needs to be removed so you need to deal with the accelerator lever return springs.  Send me your e-mail and I'll send you a pictorial I made that shows the step-by-step process for replacing that o-ring.   

Are the return springs that nasty to deal with? I'm doing my AAZ pump now and I know there will be a bit of a trial and error getting my new accelerator shaft set up.

[zuhandenheit]

I had a lot of trouble the first couple times I dealt with the return springs. But since I realized I could use a bit of cable with a looped end to pull the springs into position, it hasn't been a big deal. If you don't have one around, go to the hardware store and get a foot of thin cable and a crimp, and make a loop at one end. Take pictures so you remember how the assembly goes together, and then when you reassemble, loop the cable around the end of the spring, pull it into position, and then remove the cable. Having done this several times, it takes me just a few seconds a spring. I do usually have to fiddle with the bushings etc to get everything in the right place, as I am usually over-confident and don't take a picture.

Also, by the way, the LDA lever shaft on my pump is secured/sealed neither with metal balls nor with screws, but little metal cups. I thought maybe this is a Giles-specific thing, but the reseal kit I used had these cups -- which is lucky, because the metal is very thing and I damaged one in the process of hammering the other out of place (ie, one side is hammered to push the other out, then the shaft is used to remove the other, and then itself pushed out).

Is this how the newer pumps came from the factory? This pump has the timing adjustment at the pulley -- which I love. There's the one disadvantage that timing can't be adjusted while the engine is running, but I've always used a dial gauge and never had a need for this. The adjustable pulley is otherwise simpler, and I especially appreciate that I don't have the fuss with the fuel lines -- every time I do so, I have a bit of a concern that they won't seal again.

[zuhandenheit]

A few more comments:

I already had a reseal kit, but it did not have the LDA seal. I bought the DGK121 kit, which had the seal and those little metal cups I needed.

The kit was listed as  "Bosch VE Injection Pump Gasket & Seal Rebuild Kit for Diesel Dodge Cummins 5.9 L"

After some research I could only find one or two claims that this kit contained the right seal, so I was a little apprehensive and looked closely before opening it.

When I tried to procedure on my old, mostly disassembled test pump, I had no trouble removing the cover to access the pin. But on this pump, i really had to fight with it. I used a big socket wrench with a 1/4" socket and a flathead bit, and held the pump in a vice. The only other way I might have removed it would have been using an impact driver.

Lastly, the Giles boost pin and governor are interesting. The taper on the boost pin looks to be as extreme as could be achieved while leaving enough material to hold the pin together! This pump was designed for a bigger turbo at 25 psi. I however have a k03 at 18 psi. But my EGTs are quite good and I don't see much smoke at all. This is interesting to me in part because my last pump, which I bought also after a recent rebuild, had a 1.6td boost pin and smoked way too much between 5 - 10 psi. I had higher EGTs and the motor was not nearly as powerful. I can't overstate how much I like this pump.

 

[keycle]

I have the same leak , is it possible to access the bolt holding the pipe in place without removing the turbo?

[zuhandenheit]

I have the same leak , is it possible to access the bolt holding the pipe in place without removing the turbo?

I must be misunderstanding -- You have a leak at the LDA vent on your injection pump?

I'm not sure what pipe you mean, or why you'd have to remove the turbo . . .

[zuhandenheit]

I need a quick bit of advice:

It turns out that all is not quite well. One of the little metal cups (vs metal balls) that seals the ends of the LDA shaft is leaking. I didn't use or think I needed to use sealant. It's possible it's just not fully seated.

Here are my questions: Would it be less work to pull the whole pump or just pull off the top? I won't need to remove the top to fix the seal . . .

This is, again, one of the newer pumps where the timing adjustment is built into the pulley. So I shouldn't have to re-time it.

Also, I have to consider the fact that opening the pump is probably riskier than pulling it, wrt damage etc.

I'm pretty sure I'll pull the pump, but I'd like opinions.

[burn_your_money]

When I worked at the shop we always used a thread locker type sealant on those metal caps.

If it's the front one that is leaking, thread a slightly oversized tap into it and it should pull out once it starts spinng. Then install the new one with sealant. Make sure to have the diesel drained low enough in the pump so that you can ensure a clean surface for the sealant. If it's the back one, I'd just pull the top of the pump off assuming everything is nice and clean and you aren't risking putting dirt into the pump.

[SR Heer]

It is unlikely that the boost pin has anything to do with the leak.  There is a feeler pin that rides against the boost pin.  Around that feeler pin is an o-ring that seals against case pressure.  It's a pain to change but doable.  Worst part of the process is that the pump lid needs to be removed so you need to deal with the accelerator lever return springs.  Send me your e-mail and I'll send you a pictorial I made that shows the step-by-step process for replacing that o-ring.   

I would benefit from pictorial/tutorial - please send to my email of - [email protected]
thanks

And as far as static timing of eTDI and mTDI AHU and ALH pumps respectfully - are they not close to 1.47mm - where the AAZ 1.9TD pumps I think are supposed to be .80mm - ,82mm - correct me if wrong - and I guess the TDI pumps require a more advancement of fuel spray to work well because of their direct injection type? Is this correct?

[SR Heer]

When I worked at the shop we always used a thread locker type sealant on those metal caps.

If it's the front one that is leaking, thread a slightly oversized tap into it and it should pull out once it starts spinng. Then install the new one with sealant. Make sure to have the diesel drained low enough in the pump so that you can ensure a clean surface for the sealant. If it's the back one, I'd just pull the top of the pump off assuming everything is nice and clean and you aren't risking putting dirt into the pump.

Tyler -  is there any way by reading the part numbers on side of IDI VE pumps to distinguish whether they are 1.6TD, 1.6IDI (with an altitude compensating LDAs), and or 1.9TD pumps? I believe outwardly one can tell 1.9TD pumps by their longer output delivery valves and non adjustable boost pin from on top of LDA lid - correct? But what about the part numbers alone on outside of pumps - is there an explanation for differences between them noted by segments or specific part numbers of pumps alone?

[libbydiesel]

That's an interesting question.  If no one has opened the pump before, then the outer part number might be useful.  Because Bosch pumps are like legos, if someone has opened the pump up before, you cannot really tell by part number what is inside it, only probabilities.  I've fitted LDA tops to non-turbo pumps (modification necessary), swapped camplates, swapped boost pins, swapped delivery valves, swapped fuel distributors, swapped timing pistons, etc, etc...  I've usually build up the pump to be what I wanted from the best suitable pump case, regardless of outer part number and what the pump was originally fitted to.  Maybe I should grind off the outer part numbers afterward, but I've never bothered.