Fuel leak

[MikFish]

Hello!
1996 GMC 6.5 Diesel. 225,000 miles. Have recently discovered a small fuel leak from the 1/4" fuel line going into the mounting block for the PMD. my question is how far down the valley is the other end of that line? I am going to remove the manifold and snip the end off the current fuel line and try to re-mount if has enough slack.

2nd question: If I have remote mounted my PMD out of there, do I need that fuel line? If I am thinking correctly it is there to supply cool fuel for the PMD to not overheat. Correct?

Thanks for any guidance.
Mike

 

[Paveltolz]

Just for point of reference, there's no fuel line going into the PMD "Block"...that's the injection pump.

Are you referring to the line going into the Injection Pump (#2) that comes from under the intake manifold and makes a 90* downward turn?



Cutting a little off the end that is leaking will probably do it AND you'll need them to remain in place if you choose to move the PMD to a remote mounting location outside the engine bay since that is the line you'll need to ensure your truck runs, drives etc.

If you remote the PMD (always a good idea), Don't try running the truck w/o a proper heat sink. You are correct that the fuel in the Injection Pump was supposed to help cool the PMD. Clever idea except for the time the PMD was exposed to the engine heat after shut down when no fuel was moving through the IP.

 

[MikFish]

Thank you! it is the line attached to #2 in the diagram. How far down is the other end?
I have already relocated the PMD (with a heat sink)

Thanks for the diagram and explanation.

 

[dbrannon79]

@MikFish if you can, post some photos of which fuel line is leaking and where you see fuel at. in the photo above, #2 is a full rubber 5/16" hose that runs from the injection pump under the intake and connects to the FFM (fuel filter manager) which is bolted to the rear of the intake.

you can replace it without pulling the intake off from the engine, but it's not that easy since unbolting the FFM from the intake, the hose doesn't give you much slack to get in there to un-clamp it. the curve that this hose makes at the IP (injection pump) is very tight where it will be hard to do with using bulk fuel line unless you run some extra length to route it differently to the IP (keeping it from kinking). it's a "pre-formed" fuel line.

Chances are with the age of your truck and this hose living down under the intake over the years in the heat of the engine along with being saturated with oil from any leaks, the hose will be very brittle and needs to be replaced.

I opted to relocate the fuel filter assembly by removing the FFM and using an aftermarket fuel filter with a clear bowl mounted on the firewall. I ran fuel line up over the intake out away from all the heat. this is something you might not be able to do if you live in a colder climate. the FFM has a fuel heater to help with the cold weather.