Fuel pump on lycoming engine

I'm getting a small amount of fuel coming out of the tube on the fuel pump. Does this mean the pump is still to go bad?

Thanks
Dan Carley

It means the internal diaphragm is leaking. Replace the pump.

What airguy said. And don't even think about rebuilding the pump. There are several critical things inside that we mere mortals don't have the knowledge or equipment to repair properly. I'm running a Tempest fuel pump on my engine. Oh yeah, there's a procedure for replacing the pump so that the internal cam is "down" when inserting the finger on the new pump. Someone else will have to provide that information because I've not done it before.

snopercod said:

Oh yeah, there's a procedure for replacing the pump so that the internal cam is "down" when inserting the finger on the new pump. Someone else will have to provide that information because I've not done it before.

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Once the old pump is out, you can press up on the pushrod and have a friend slowly rotate the prop. You'll feel the rod push down then retreat back up. It has about 1/4-3/8" of travel. If I remember correctly, it will move once every two revolutions of the crank. If you don't feel it moving with the prop moving, it is in the retracted position.

Larry

Do a search here and you will find some very helpful posts. I have changed out a couple. The first one was a nightmare. The second super easy. What makes it tough is the spring loaded pump lever engages with the push rod that drives it before the threads of the bolts engage.
Yes, rotate the engine until the push rod can be pushed up with your finger as high or as far as it will go. Then get yourself a ball end type Allen wrench as normal Allen's interfere with the pump case. If the pump is square to the case, and the lever is under the push rod, it will screw down very easily. Alternate tightening the bolts a few turns on each side to keep it square.
I cut off the Allen wrench so I could fit it into a socket and used my palm wratchet, torque wrench, and extensions. Again, you need the ball type Allen wrench to clear the pump case. You need one hand to hold the pump square and one to turn the bolts.
It isn't hard at all if you do these little things.