Started the truck this morning, let her warm up. Ready to leave walked out to the truck saw a puddle under the drivers side(had a heavy dew this morning). Decided to crawl under and check, just in case. AH-ha diesel, pop the hood lift pump is leaking. All the wrenchs are at the shop. Had to get to work, figured I would just buy a wrench when I got to town. Anybody know what size the banjo bolts are? Fuel pressure stayed normal. Just in case the banjos are tight anyone heard of the lift pump developing a leak? I did replace the lift pump about three weeks ago. I would have though that if it was going to leak it would have done it then.

 

So I guess no one else has had a lift pump leak. Went and bought wrench (17mm by the way). Left the truck running it has quit leaking on it's own ???

 

bkay,<br> It sounds like you have a very well trained truck. ;D I haven't had to mess with the lift pump yet, (probably will in the near future,,, pressure getting weak), but did you use new washers on the banjo bolts when you replaced the pump? I would imagine it would be advisable,,,, right? I can't seem to find a dealer in my area that is even aware of the lift pump issues and I'm tired of fighting with the one where I purchased my truck (service manager with an attitude), so I'm watching it closely and plan on getting a pump from Cummins to install myself.<br> Glad your problem has dissappeared! ;D

 

Well it came back again this morning. Last night i checked the banjo bolts they were tight. Inspect the pump area no fuel leaking, wiped it off. This morning puddle of fuel on the driveway. Crawled under the truck the inlet banjo was not leaking (shouldn't it is not under pressure). Looked under the wheel well at the lift pump outlet it is dry also. The fuel is leaking from the backside of the pump. It only does, it appears when the ambient temp. is cool. When the engine warms up the leak goes away. I'm thinking a weak seal or a hairline crack in the pump housing. I'm going to to local Cummins shop to see if they will let me have a new pump, this one is only three weeks old.

 

Let us know what you find out.

 

Ok Fri.- Mon. had no leak, ambient temp. was around 55 degrees each morning. I had picked up a pump on Friday. Tues. morning temps. were back down to mid 40's and the leak was back. Changed the lift pump out last night, overnight temps. dipped to the mid 30's - new pump, no leak. Good fuel pressures just like the last one. Warranty on the lift pump through Freightliner is - they will test the pump and see what is wrong with it if they find no problem they will bill for the cost of a new pump. Good luck collecting on that one boys! I know they aren't going to check the pump at the lower temps. that I was having problems with.

 

Had the same problem. Had my lift pump relaced and less than 7,000 miles later it started leaking. I tighten everything and it still leaked. I bit the bullet and had one put in the tank.

 

Wasn't my lift pump but I had an irritating leak from the bottom banjo on the filter housing (after much looking and laying under my truck to figure it out). Happened to me right after a filter change (which was weird). Mine would only leak after shutting it off (again weird as the pressure was gone). I think it was a crush washer leaking. I got tired of it and went with a Vulcan big line kit, no more banjos, no more leaks.

I would suspect the banjo washers, they are delicate little devils it seems.

 

What I want to know is if I can put an in line pump in front of the new in tank pump. I say no because the in line pump will out work the in tank pump. The guys at Oregon Diesel say that a BD pump will work fine. What do yall think?

 

bkay,
I would be calling the guys who are going to check out your returned lift pump. Cause all their going to do is invoice you after they trash it. I'd put it in my tool box and keep for a spare. You'll probably discover another simple item causing the real problem. But no matter what, it's your pump if they make you pay for the one you've now installed.