Lost prime

[CoyleJR]

My LBZ just lost it's prime; after sitting 24 hours parked facing up a steep hill. The truck started right up after a few pumps on the primer pump. The truck has a half tank of gas, no leaks and runs great. Does anyone have any thoughts about the cause of the lost prime.

Thanks in Advance
John

[DmaxMaverick]

Not at all uncommon. Any fuel system leak will be exploited by the slightest pressure/vacuum, over time. Although it may not be a problem during normal running, time can have an affect. The fuel system manages minor air leaks very well, but yours just crossed a threshold. Probably a very small leak at the filter gasket. Unless you see external fuel leakage or it gets worse, I wouldn't worry too much about it.

[LanduytG]

Loosen the bleeder screw and pump it till all air is out. Close bleeder and pump primer till hard. I've seen this many times and the procedure I described has fixed it unless its a leak. For what ever reason it seems to make a difference.

Greg