Fuel pump tip
Posted: Thu Jan 15, 2009 12:11 amI just finished rebuilding my jeep fuel pump and ran across what it probably a common occurrence. The primer arm on the g503 and g508 fuel pump is a steel shaft with a flat spot where the cam driven pump arm normally goes. When you pull up on the primer arm, the shaft rotates and the round portion of the primer shaft pushes the pump link down.
On my jeep the pump arm had a wear point about 1/32th of an inch deep. What this means is that the primer shaft would not actuate the primer link nearly as far as it should... resulting in poor priming performance... it took A LOT of pumping to get fuel into the bowl and up to the carb.
The solution was to weld up then file smooth the wear point on the link. After installing the pump on the jeep I had a full prime from nothing in about 10 pumps.
Since the CCKW has a lot farther to pull gas and the same primer setup next time you have the pump off look at the link and make sure there is no wear.
And by the TM the primer arm is to be in the DOWN position after priming the engine.
On my jeep the pump arm had a wear point about 1/32th of an inch deep. What this means is that the primer shaft would not actuate the primer link nearly as far as it should... resulting in poor priming performance... it took A LOT of pumping to get fuel into the bowl and up to the carb.
The solution was to weld up then file smooth the wear point on the link. After installing the pump on the jeep I had a full prime from nothing in about 10 pumps.
Since the CCKW has a lot farther to pull gas and the same primer setup next time you have the pump off look at the link and make sure there is no wear.
And by the TM the primer arm is to be in the DOWN position after priming the engine.