For the last 4 years starting June of 2006, driving 28,453 miles on B100 only I have had to install 2 new Lift Pumps. The last one is starting to decrease in output pressure from 6psi to 5psi with a longer time to build up pressure on start up.
What is the answer for the pump to last longer ( a piston pump) or what?

 

hey-Hey!!!,
What have you been using that failed so quickly?
cheers,
Douglas

 

I"m assuming the diaphragm pump that comes stock on these trucks have a natural rubber diaphragm. As I'm sure you know with Biodiesel, its a solvent that eats away at natural rubber materials. The stock lift pump is garbage anyway, a piston pump should prolong your surface life much more while giving your engine better fuel pressure anyway.

Your dipstick wouldn't happen to be going up would it? When the diaphragm fails, it leaks diesel into your sump.

 

kind of a personal question isn't it DZL?

 

I have been able to change the diaphragm pump before it starts to leak in the sump so far.
Is the only option the piston pump?
What about the o-rings on the piston pump?

 

Good one, I think we should leave his dipstick out of it...

 

Funny thing is... I thought about that one after I typed it and thought "Naaaah... no one will go there. We're having a professional conversation here"..... Should have known

 

How would it be to install a HFP702 Piston Lift Pump?
Think it has a pressure rating of 8psi and is used on the 4B Cummins Engines.
Could not find out the flow rate.

 

Sorry guys, I couldn't resist.

 

The following part numbers are for revised Piston Lift Pumps for the B Series.
I think the changes were for Noise, Low Sulfur Diesel, And Biodiesel Etc.
CUMMINS LUCAS
DELPHI
CARTER
3918076 HFP702
3930349 ?
3932228 ?
3933256 ?
3936320 ?
4944714 ?
4988751 ?
What are the HFP...numbers??