Fass not pumping.

[clrussell]

I tried searching so apologies if this is redundant.

I got a used fass for my truck. I think it’s a 165. I paid $0 for it.

It runs, won’t pump fuel. I pulled it apart and can’t see anything physically wrong.

Does anyone know if there’s a spec for gear clearance on the pumps? Or will a motor assembly fix my problem? I don’t care to buy one, I just don’t want to order a motor assembly and it not fix the problem.

I bench tested the motor with it apart and everything spins as I would think it should.

 

[DuramaxRamRod]

Did you bench test the pump or in the truck?
All the pump passages clear? Return line still have the check ball and spring?

 

[clrussell]

Did you bench test the pump or in the truck?
All the pump passages clear? Return line still have the check ball and spring?

yes all clear, yes return spring and ball, bench test on bench. Can watch the gears turn

 

[Bdsankey]

yes all clear, yes return spring and ball, bench test on bench. Can watch the gears turn

What happens if you pack the gears with grease then try and get it to suck fuel? I'm wondering if it just is airlocked from being worn.

 

[clrussell]

What happens if you pack the gears with grease then try and get it to suck fuel? I'm wondering if it just is airlocked from being worn.

I can try that. It does pump fuel if you prime the hell out of it. However if you shut it off it won’t self prime

 

[Bdsankey]

I can try that. It does pump fuel if you prime the hell out of it. However if you shut it off it won’t self prime

Can't say I've had that happen before. That would lead me to believe the gears are worn out to the point where the don't create enough of a seal to keep fuel in the pump housing.

 

[clrussell]

Can't say I've had that happen before. That would lead me to believe the gears are worn out to the point where the don't create enough of a seal to keep fuel in the pump housing.

agree, that was my thinking as well

 

[TheBac]

Ah, but the question now is, Is it warranty-able?

 

[2004LB7]

wouldn't a check valve keep fuel in the housing?

 

[clrussell]

wouldn't a check valve keep fuel in the housing?

no check valve I can see

 

[clrussell]

Ah, but the question now is, Is it warranty-able?

maybe to the original owner if it was registered, and they have the paperwork. Fass is hardcore on warranty papers

 

[slowlml]

Ive got into that a couple times with fass. Unless you know the original owner and they go through fass for you then youre sol.

 

[clrussell]

Ive got into that a couple times with fass. Unless you know the original owner and they go through fass for you then youre sol.

yup.

But like I said it was a free purchase, so I don’t mind to spend the $250 on a new motor assy if it fixes it

 

[JoshH]

Does it have the little ball in the housing that goes between the pump body and the filter base?

 

[clrussell]

Does it have the little ball in the housing that goes between the pump body and the filter base?

yes

 

[JoshH]

It sure sounds like pump wear might be your problem.

 

[clrussell]

It sure sounds like pump wear might be your problem.

Thanks Josh, that’s what I thought too but wanted to run it by others

 

[clrussell]

It sure sounds like pump wear might be your problem.

Thanks Josh, that’s what I thought too but wanted to run it by others

 

[clrussell]

I went on a whim and called fass. They say it’s a suction side issue on the truck. So im going to do a bucket test whenever I get my new filters in and see what happens.

 

[LBZ]

Tolerances on a gear pump like the FASS and AD are pretty high for wear. You might lose efficiency but not likely to lose complete flow. There would have to be missing pieces or significant wear that would easily be visible. Usually the brushed motor goes up in smoke long before the pump wears out.

Not saying it’s not worn out as I haven’t put hands on it, but I tend to agree with FASS. Possibly a cracked housing or poor/blocked suction line or a suction line connection sucking air is where I would be looking.