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Fuel line routing at rear of engine

MrMarty51

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Take a garden hose and rinse out the valley with water. Park on a slope to drain the water out of the valley. If You have an air compressor and blow nozzle, can also use that to blow out any water and fuel left standing in the valley.
Might take a while of driving and running to refill the valley if the leak still persists.
 

JMJNet

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Check the FFM, the older design have some sort of grommet where the electrical wires come out.
That grommet, with age, will be out and it may leak intermittently, at least that happened on mine.

I ended up buying a new one from Amazon.
The new design is a complete seal instead of a gromet.
I added some sealant on the new one just to make sure.
 

topeju

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Yes, we replaced the gasket around the WiF sensor in the FFM when we were debugging the leak. I rinsed the valley with water on Monday, but soon after that, we lifted the rear of the car up in order to service the rear brakes, and had to order some new parts for that (which should hopefully arrive today), and I haven't had a chance to see if the leak persists now.
 

topeju

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Sigh, it is still leaking. Intended to move the car inside the garage, and it wouldn't start because it wasn't getting enough fuel due to there being air in it. Let the air out, and now it barely runs (had trouble climbing up the very slight incline into the garage), and leaks fuel, again from the same place. I'm pretty sure the problem is the FFM itself, but couldn't see anything obvious.

What would be the best option, get the ACDelco FFM from Rock Auto ($180 with express shipping and import duties), or see if some local diesel (or even tractor) repair shop or whatever might have a completely different fuel filter assembly? In either case, I think I'll raise the filter up a bit, as it is currently underneath the hoses to an Eberspächer heater, and thus a bit difficult to operate on.
 

topeju

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Ah, moving the FFM for testing is a good idea! I think that because I'm a bit schedule constrained right now (need to get the truck inspected by the 24th), I'll order a new FFM (because I still suspect it the most, as when we pulled the intake, the FFM was the only part that was moist in addition to the valley floor), but while I'm waiting for it to arrive, I'll test the old one by moving it off to the fender well.

I haven't looked at the IP weep hole though, didn't even remember it existed.
 

Husker6.5

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And fuel leaking from the IP weep hole would fill the valley and air movement from the fan/driving would leave a film of the valley pooled fuel on the FFM.
 

topeju

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Ah, indeed it would. The weep hole is then a second suspect. I hope it can be plugged without removing (much less replacing) the IP?
 

Husker6.5

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It functions much like the weep hole on a water pump does. You need to check it (inspection mirror and a flashlight to see the underside of the IP) to rule out the IP being bad, and in the meantime pray that it's the FFM that's seeping fuel. You did check for the obvious cause of the old gasket sticking inside the cover when changing filter elements and then installing the new gasket and having a doubled up gasket causing the leak?
 

Husker6.5

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And it would also explain the recent start-up problem symptoms you described, as fuel seeping from the weep hole would create air/no fuel inside the IP and result in prolong cranking time until it fills and then fire and runs rough until all the air is cleared from the IP.
 

Will L.

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The weep hole is in between fuel and oil. If fuel seal leaking and you plug it- all that fuel will go i to the oil pan ruining the bearings and entire engine.
(Not your current issue but sometimes the oil seal leaks and the fix to keep driving is put the crankcase under deep vacuum Through a oil catch can to buy time.)

Unfortunately there is no trick for buying time with a fuel leak- kind of a fire risk and all. If it were zombie apocalypse scenario then First you put a couple fire extinguishers, one in cab and the other in the bed- and I mean the big ones. Then you add more liftpump to fight the air getting in. Then plug the rear valley drain hole and use a lift pump to scavenge fuel as it leaks into the valley to a jerry can in the bed. (Filter that fuel before dumping it back into the tank.) Then check the engine oil every time before driving to work and again before driving home. If you go 100 miles one way, stop half way to check oil.
You can get some diesel into the oil as a sludge washing action, but with modern crap diesel- I think 1 quart of diesel would ruin bearings in 40ish miles.

There is actually a couple Hummers running around right now with the old school mechanical lift pump instead of electric! I have major concerns for them because Ive seen many engines get ruined from minor bladder failure pumping fuel into the crankcase, and that was with real diesel. The alcohol in new diesel would do it much sooner.
 

topeju

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Ah, I'd misunderstood the purpose of the weep hole. Yeah, plugging it would not be a good idea.

Yes, the old gasket is out (or, actually, both old gaskets as I currently have the third filter in the FFM).

I really hope the problem is with the FFM (especially since the new one is on its way), as I really can't afford a new IP at the moment. Or can it be repaired?
 

topeju

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Yes, that might be extra challenging here in Europe. Oh, well, still hoping the problem is with the FFM, haven't had a chance to check it yet.
 

MrMarty51

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Remove the intake manifold, then run the engine, you should be able to see then, exactly where the leaks is coming from.
leroy diesel has the FFM with the feed the beast mod if You want to go that route.
 

topeju

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Finally found and fixed the leak. Earlier last week we moved the FFM and saw that it wasn't the source of the leak. We also tried to look underneath the intake with a mirror and an endoscope, but found nothing. On Thursday, I ran the engine for a bit and then pulled off the intake, and then looked around, but still didn't find anything conclusive. I wasn't sure I saw the weep hole, but one of the injector lines looked a bit suspect.

On Saturday, we finally ran the engine, and I could immediately see there was diesel spurting out from the injector line. On closer examination, the line was quite loose, and the nut holding it could be tightened by hand for almost one full turn before we had to switch to tools. We completed assembly yesterday, and had the car running for half an hour, with nary a drop on the ground. It also responded quite a lot better to throttle input and ran perfectly well.

Now I only need to adjust the rear brakes and fix the front grille and I can take it back for inspection...
 

Husker6.5

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Though frustrating, it is always better on the pocketbook (but not necessarily the sanity) when you can track the problem down to an operator error (a loose bolt, a forgotten injector line nut, an unplugged electrical connector, etc) than a major component failure.
 
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