Posted 1/5/2009 13:59 (#558453 - in reply to #558410) Subject: Re: C-12 Cat Fuel check valve?
I agree with catman95. When replacing the fuel return check valve, don't overtighten them! I believe the torque is only 28 lb ft. If you over torque them, it distorts the internal bore, and can cause it to stick open or completely shut. Question: Does this engine already have a fuel hand priming pump on it? If not, I have seen where just installing a hand priming pump has helped this situation. Hand Pump=137-5541 and its gasket=1P0436. Do the return check valve first(most likely culprit). Do you have a fuel pressure gauge? If you have it attached, AND the engine has the hand priming pump installed, AFTER you shut off the engine, you should have roughly 60 psi held in the fuel system on the fuel pressure gauge, This is normal. It tells us the fuel check valves are holding= they will create fuel pressure during cranking for the next start-up of the engine.