fass problems (again)?

[Diesel Power]

i dont know why but i have never had this happen before. this is a standard springed fass 150 duel filter set up, when under stock power the fass will drop 3 psi, it idles at 19 psi, but then when i let of the peddle just coasting, i hit the brakes and now the psi jumps up to were it should be 22 psi, what has gone wrong with this pump. (air)? it happened after i replaced the motor and t-block on this same truck. yes i put new seals and cleaned the mounting area, no leaks or any thing. just a wierd pressure issue. thanks

 

[WCounts]

Sounds like a problem with the pressure relief valve.

Install a in line fuel pressure regulater and cap off the return port on the FASS. and see if it does the same thing.

 

[michaelRitz]

I just ordered a FASS, now maybe I wish I would went with something else. This is like the 3rd problem I have heard about in a couple of days. But there is a lot of them out there so maybe I wont have much trouble with mine.

 

[Diesel Power]

it on the same customers truck that had problems last month, i'll have to probably put a new unit on!