Lift Pump Leak

[79Vette]

Has anybody ever seen a lift pump leak externally? I replaced it in 2018 and the truck starts and runs fine, and I don't have oil getting into the crankcase.

There is a small amount of diesel dripping down off the bottom of the engine, and I know the injector pump is leaking (saving up for a replacement pump/injectors in the next month). But it also looks like the lift pump itself is leaking from the crimp at the perimeter of the housing. I cleaned the pump with degreaser and sprinkled baking soda on it, and after driving for an hour its still dry on the top but most of the baking soda has been washed off the bottom of the pump and it is wet with what seems to be fuel. There is no obvious dripping leak with the engine idling, but the engine crossmember is also soaking with fuel after driving for a couple hours. So it has to be coming from somewhere.

I'm planning to change the pump tomorrow and see if the leak stops, but was curious if anyone else has had these leak externally. Its kind of a pain to change them, and I was hoping it would last more than 4 years...

 

[87cr250r]

Not personally but there is a hole in the case right above that crimp so that it will leak externally when the diaphragm fails. Otherwise it will fill your crankcase with diesel and damage the engine. The diaphragms on lift pumps do have a finite life.

 

[cucvrus]

Disconnect the batteries and change it from the top. You can remove Gen with the wires intact and access the lift pump from top. Very easy. Leave everything loose till you get everything started hand tight. The bottom 2 m 6 push rod cover plate bolts are the only 2 you need to tighten from the bottom. Good Luck. 45 minutes max on that job.

 

[nyoffroad]

It seems odd and is uncomfortable changing it from the top but if you do it from the bottom you will NEVER do that again! What a PIA!

 

[cucvrus]

Funny story. My Wife was saving money for a road trip she was going on with a church. She asks if I knew of any way to make money. I had a driveway full of CUCV's at the time and I was rebuilding them. Everyone I rebuilt I changed the lift pump on. I told her I would give her $35. each to change the lift pump. I showed her the bolts and sizes. She struggled with the first one and was determined to get it and not give up. The next truck had the alternators off of it and she asked me if she can change it from the top. I went out and looked and said sure it looks much easier. From that day on I changed them all from the top and removed the Gen 2. She made out with $250. and also learned to change starters and alternators.

 

[Mullaney]

Funny story. My Wife was saving money for a road trip she was going on with a church. She asks if I knew of any way to make money. I had a driveway full of CUCV's at the time and I was rebuilding them. Everyone I rebuilt I changed the lift pump on. I told her I would give her $35. each to change the lift pump. I showed her the bolts and sizes. She struggled with the first one and was determined to get it and not give up. The next truck had the alternators off of it and she asked me if she can change it from the top. I went out and looked and said sure it looks much easier. From that day on I changed them all from the top and removed the Gen 2. She made out with $250. and also learned to change starters and alternators. View attachment 880297

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