Engine/Transmission (1998.5 - 2002) Lift pump leaking fuel!

[snowracer69]

Went out this morning to start my pickup... temp was about 32*F. Let the grids cycle, cranked her the normal time, but she didn't fire (need to start cycling twice, as I can't plug her in)... so, fired her again and she started right up. Went back inside and let her idle about 5 minutes... came back out and I had diesel dripping off the bottom of the front diff. !!!! So, I looked and looked and couldn't see anything, and was late for class as it was, and fuel pressure was fine, so I left. Came back to my pickup after class and I had a nice little diesel spot under the front diff again. Climbed underneath and it was all the way down the front drive line and on the transmission lines. So, I investigated a little harder there, but still couldn't find where it was dripping from... it was coming down from somewhere above the starter. Got home and climbed under and checked everything... can't find where it's coming from!!! All my banjos are tight, all the injector lines are tight... the only place that seems as though fuel has come out of it is the very bottom of the lift pump where the wiring goes in!



Anybody else have this problem? FP is still running 14 PSI at idle and 10-12 at cruise, and pump sounds fine when running.



Oh, after wiping everything clean I let it prime w/ a starter bump and nothing was leaking down from what I could see



What happened, and is there reason to go get a spare LP just in case?



Josh



edited to add: When it was dripping off the front diff it was a drip about every 2 seconds, so wasn't a slow leak... didn't get a good look at the LP when it was doing this though, so am not sure if it was coming from there or not.

 

[Sean Flanagan]

I had a problem once where a fuel line cracked right at the banjo bolt. It was the fuel return line from the Injector pump. It would leak occasionally, but when it did, the fuel would travel along the fuel line and drip off somwhere other than where the crack was, making it hard to find.

 

[snowracer69]

Ok, it did it again this morning and now I know for sure it's coming from the bottom of the lift pump (or possibly the back side where I can't see) but it's DEFINITELY NOT coming from one of the banjos or a fuel line. .



So, what do I do? Am considering going to the dealer where it was replaced last time and having them look at it... problem is that being BOMBed to the hilt bothers me a little bit... they were cool with it before, but might be a new tech or service manager...



They've just given me warranty parts to put on myself before, think they'd give me a LP and I could do it myself? I know it's not a hard swap.



Josh

 

[Phil Stuart]

Just a thought

Josh,



you may want to check the fuel/water separator drain valve to be sure it's closed all the way. The way the drain hose is routed, it'll dump fuel right on the front differential.



Phil

 

[snowracer69]

Phil,



Thanks for the input, but I know it's not that. I have my drain hose routed in such a way that it wouldn't be leaking on top of the starter, and secondly, I checked it already too.



It's definitely coming out of the lift pump, and after I get done eating lunch I'm gonna take my chances and go see what the dealer says.



Josh

 

[Red Rocket]

lift pump leak

Snowracer,



I am working on the exact same problem as you are right now, I lit it up good, looked from below and above and finally felt everything around it. Leak is definitely coming from around the wiring plug for the LP. I think I'll call the dealer, but hopefully it gets covered under warranty.



Nick

 

[Whitmore]

I would take a strong look at the cap on top on the pump, I bet the fuel is running down the side of the pump and dripping off the wiring connection, simple to do , there are 3 studs that hold the lid on, they also act as the mounting studs for the pump, if it were me I would remove the pump and take the 3 studs out, then you can clean the inlet screan and put the lid back on before putting pump back in.



Cheers, Kevin

 

[snowracer69]

Whitmore,



That was one of my thoughts as to what it would be. I have a Carter pump that I use for my transfer pump between my aux and main tanks, and I have had it all the way apart before... . not much too them, and wouldn't be hard to make one start leaking out the cap.



My question is why it would only do it when the pickup/diesel is cold? Shouldn't have any more pressure on it (FP gauge doesn't show that it does).



Mine goes to the dealer Tuesday afternoon for a fix. Service manager told me they still stock LP's (I thought they weren't allowed to?) and he said if they find that it's leaking out of the pump, it'll be replaced under the 100k warranty. I HATE taking my pickup to the dealer, for fear of warranty issues as well as I hate letting those lot monkeys touch my pickup and drive it!!! AARRGGGGHHHHHHH... . I'm gettin' all worked up just thinking about letting them look at my baby, let alone work on her. They'll probably screw-up my FP line that comes out of the bottom of the filter when they take it out to change the pump... . grrrrrrrr.



Josh

 

[Cummins4Life]

Slip the service manager a $50 and see if he'll let ya back in the shop to watch...

 

[zman]

mine's leaking too...

I went into the garage this morning and smelled diesel fuel so I knew something wasn't right. I looked under the truck and there was a spot about 2" in diameter. Once I got under the truck, I could see that I had fuel all over the starter, the front driveshaft and differential. I traced it back to the bottom of the lift pump where the wiring goes in. I can't see behind the pump, so I don't know for sure where the fuel is coming from. I did notice however that one of the nuts (the one towards the front) that holds the lift pump to the mounting bracket was missing, so maybe all I need to do is install another nut to seal the cap. I hope it ends up being that simple. If not, looks like another lift pump will be in order. If so, it will be the 4th...



Steve

 

[snowracer69]

Zman, you just described my experience to a 'T'!!! Except that I'm not missing the mounting nuts... figure mine may be loose though. Am going to give her a once over this afternoon once I'm done studying for the day (still have about 8 hours of homework to do today) and maybe I'll save a trip to the dealer.



Josh

 

[snowracer69]

Just back from the dealer (actually 'bout 2 hours ago)...



LP was replaced, check new thread "New Lift Pump... again!" for what happened.



Josh

 

[zman]

fixed - I think...

Well, I replaced the missing nut and tightened up the other two. I appears that the leak has stopped - for now. I had no idea that there was a separate cap on the LP or that the mounting studs also held the cap on. Thanks for the info!



Steve