Who has opened up your bad lift pump?

What causes low pressure with these pumps. I took mine apart and breifly inspected it and it looks new. The viens and houseing etc are not worn.

I dont have time to inspect it further cause im blowing this town for the mountains and hunting.

only thing I can think of is the electric motor part , armature shaft gets loose maybe.

Anyone else know?

Rick

 

Ive been told by 35 year diesel mechanic and Cummins specialist that a LOT of the trouble is caused by air in the fuel which causes cavitation within the lift pump. Lack of lubrication causes their early demise as well. Look into a FASS or Fuel Preporator (SP) - they remove the air and allow you to trash the stock lift pump.

 

Failure is due to the relieve valve inside the pump which consists of a ball and spring on a seat.

A few things happen...

Seat can wear cause low pressure

Ball can get calkeyed on on the seat causing massive loss of pressure with no warning.

Whole relieve valve can come loose in the housing and end up just flopping around like a dead fish in there.

And last but not least the spring can wear allowing the ball to pass into the spring which in turn causes low pressure.


The rest of the pump seems to be pretty good and if the relieve valve was of a better design I am sure the problems would be reduced big time.

 

I second the notion on the relief valve- it sometimes even gets hammered through the seat!
I've changed to soft rubber lines and this made my problems with the holley blue go away. (Same troubles as with the stock LP)

AlpineRAM

 

The valve must be under the rotor and vien houseing where you cant see it or get to it with out destroying the pump. Unserviceable .

For $150 bucks that pump is a piece of crap. It should be serviceable.

Maybe ill fill the bottom where the valve is full of epoxy and get an external regulator with a bypass returning to a "T" behind the inlet.
Hell the pump viens etc. look like new.

Thats the first and last lift pump l will buy.

Next time it well be a F.A.S.S. system. Or if I can find some kind of better pump off something else,