Injector pump leak

so additional info; now i'm even a little more confused because in yesterdays test to find the leak....there was not visible leak while the truck was running (although I only let it run for a few minutes). but then this am (about 12v hours later) there was diesel in the valley and another small puddle on the floor. So what would make it leak only after it is shut off? is there some back pressure release valve like on a garden hose? thanks in advance

jaredsalinsky said:

so additional info; now i'm even a little more confused because in yesterday's test to find the leak.... there was not visible leak while the truck was running (although I only let it run for a few minutes). but then this am (about 12v hours later) there was diesel in the valley and another small puddle on the floor. So what would make it leak only after it is shut off? is there some back pressure release valve like on a garden hose? thanks in advance

Click to expand...

I'm not sure I can answer your question other than to say it may just be leaking more than before because the leak is getting worse. And you're using it more.
Many years ago, I had a leak in the valley and traced it to the secondary pump (I believe it is called the Accelerator pump?) on the bottom of the IP .
When I had it rebuilt, they said that it was a common problem with the pump I had because when it was originally made, they used a steel piston on the pump and the sleeve the piston moved in was aluminum.
Did you just recently clean the valley and the drain hole out in the back of the valley?
Does the bottom of your IP look like it has been sitting in rusty water?
Alot of the trucks sat outside for long periods of time with a plugged-up valley drain tube.
BH

yeah so I think you're right that (at some point) it may have been sitting outside for a while because as you suggested the bottom of the IP is rust colored. And after doing a lot of research on the forums I realize these IP leaks are not uncommon. The thing that is perplexing me is that it didn't leak while the vehicle was running; rather it leaked (kind of a lot) after I shut it down (and for the next 12 hrs). I'm trying my hardest to not go diving into this motor; but as time goes on I feel it may be inevitable. And then of course once you start digging around you 'find other crap that breaks or looks bad, or bolts are seized or broken'. Or 'while you're in there you may as well do this and that' and pretty soon you're looking at $5000 of work!

jaredsalinsky said:

yeah so I think you're right that (at some point) it may have been sitting outside for a while because as you suggested the bottom of the IP is rust colored. And after doing a lot of research on the forums I realize these IP leaks are not uncommon. The thing that is perplexing me is that it didn't leak while the vehicle was running; rather it leaked (kind of a lot) after I shut it down (and for the next 12 hrs). I'm trying my hardest to not go diving into this motor; but as time goes on I feel it may be inevitable. And then of course once you start digging around you 'find other crap that breaks or looks bad, or bolts are seized or broken'. Or 'while you're in there you may as well do this and that' and pretty soon you're looking at $5000 of work!

Click to expand...

That's all part of owning a High Maintenance Money Wasting Vehicle (HMMWV)
don't tell me you thought the acronym stood for something else.

I'm no expert but when your truck is running the fuel has some place to go. when it shuts off the pressure that was built up between the mechanical lift pump and the IP bleeds off through your weak spot in the otherwise closed system.

RWH here on the boards might be able to explain it better as he works on them every day.
I may not have used the right name for that little pump at the front bottom of the IP but if you're not seeing any leaks coming from the lines going out to the injectors most likely that is where the leak is coming from.

yup agreed. well i'll let you know how it goes..
thanks

jaredsalinsky said:

yup agreed. well i'll let you know how it goes..
thanks

Click to expand...

Copy that.
It's all part of love hate HMMWV relationship.
Let's hope you stop the bleeding way short of $5,000
BH