[Explosives87]

I have a 91 that the lift pump went out and replace it, I had the truck running but, it ran for a while then died so I thought that it was air in the line so I crack the injector lines, and primed the lift pump manualy til I had fuel coming out of the injector lines, then crank it and it started again so I let it run a while and it died again, and I have replace the fuel filter two days ago.

 

[Gatekeeper]

Bleed it again.
If it has air, the flex hose to the lift pump is probaly not tight and you are sucking air. Any where from lift pump to injection pump would show a wet leak from lift pump pressure.
Putting the threaded fitting in the new pumps can crack the housing, some are really cheap, and cause a leak. (Don't ask how I know! I fixed it with JB Weld.) If I have to replace another pump, I'll put a new fitting on it.

 

[Philip]

If you over tightened the inlet fuel fitting it can crack the casting. This allows air into the system. When it cracks it will be on the bottom side of the boss where the inlet line goes in.

 

[Greenleaf]

R&R of the lift pump or a fuel filter for that matter is a straight forward job. Minimal bleeding (if any) is all that's required. I too believe if your having a problem, it aint cuz you didn't bleed enough air, rather you are drawing in the air.