Bruce M

I have been running 100% Biodiesel for the past 7 years with a 2 micron filter prior to the lift pump.
Have been changing the 2 micron filter every 1500-2000 miles in the last 70,000 miles and never changed the OEM filter which I think is 10 microns.
Also the lift pump only gets about 10,000-15,000 miles when I have to change it.
Was thinking of adding a piston lift pump and moving the 2 micron fuel filter after the lift pump and prior to the OEM filter.
Think it will last longer under pressure instead of suction.
Has anyone added a second fuel filter after the lift pump?
If so did you use steel or rubber tubing to make the connections.
In my case the rubber would have to be Viton.

cougar

Have you considered using a pusher electric back by the tank and eliminating the mechanical pump?

Bruce M

Was looking at a Walbro FBR-22-2 electric pump, but already have a piston lift pump that I can use.
The problem with Biodiesel is the rubber diaphragms and rubber lines don't last.
The piston lift pump only has rubber in the check valves and they could be made of Viton which will stand up to Biodiesel.

cougar

The previous owner of my 92 put on a big filter in line as you are thinking. All it did was restrict the fuel flow and didn't do the lift pump any good. That is why I suggested the pusher.

Bruce M

Was the big filter before or after the lift pump?

cougar

Post pump. There was probably a good 3' of hose running to the firewall and back.