Holley keeps draining into engine

[1969mach1351]

My buddies Holley 850 keeps draining the fuel into the engine when it sits. It will do this in only a week and then the floats stick. I rebuilt it (I've done many with no problems) and starting having this problem again in about 4 months. The carb is less than 5 years old and is in good shape other than this problem. What is the reason for it to keep draining the bowls?

 

[ratio411]

Is it draining onto or into the engine?

 

[1969mach1351]

into

 

[pabear89]

Internal leak, Check the power valve and seal.
the Check ball in the pump, warped metering block.
And if the float is sticking after bowls empty the needle&seat is set too high.

PB

 

[Max Power]

It is very common for Ford fuel pumps to not release fuel pressure properly. The residual pressure forces its way past the needle and seat and leaks into the engine. I would try a new fuel pump as well.

 

[ratio411]

What he said...
I lean to ruptured PV or split gasket at PV.