I have, what I believe to be, a fuel pump on its way out. Anyone here know if there are any components within the fuel pump which might not be compatible with biodiesel? (i.e. seals, gaskets, etc)

 

Lift pump, or injection pump?

 

Its the lift pump. I have a Bosch replacement on order already. I plan to take the old one apart to see what failed.

 

If it's for your 2001, that right about the time ford switched from rubber diaphragms to Viton. Rubber and bio don't work very well together. I'll bet you find the diaphragm "rotted" out.

 

I never knew that. I was always under the assumption that all components in the fuel system were biodiesel compatible. I hope the replacement is compatible.

 

My bad.............I went back and looked. It was the 91-92 model year when Ford changed to Viton. Your replacement should be good to go!

 

Kinda what I thought. I appreciate you verifying that. But I will point out that when I dropped the fuel tank to do the in-tank mods, I noticed the two vent hoses coming off the top of the tank were made of rubber. They were soft and mushy. So from that discovery one could say that these rigs aren't 100% biodiesel compatible.

I am looking forward to seeing if the failing pump is due to a biodiesel incompatibility. I will post up any relevant information when I find out.

 

So last week I finally had a chance to take the fuel pump apart and found absolutely nothing visibly out of sorts. The brushes were fine, as were the windings. The pump portion and bearings seemed fine and not the least bit loose or sloppy. The pump screen was nearly spotless. Any and all seals were firm and intact without any signs of softening or degrading. Just by visual inspection, I could not find anything wrong with the pump. In fact, it was very clean and it looked good.

It had been running noisier than normal the past month or so, and I have been having low fuel pressure issues, which is why I replaced it to begin with.

I have run over 2000 gallons of biodiesel through this pump, (I have almost 150k miles on the truck) and can confirm that its components are biodiesel compatible.

 

Good stuff to know...