Leaking fuel pump

[JDanno]

Thirty hours on new engine
I was testing for leaks in the fuel system as I had noticed a fuel spot on the floor after the last flight after shutdown. Throttle 2/3, mixture cutoff, boost pump on and I get quite a bit of fuel out of the fuel pump from the overflow line onto the floor. Is this normal? After thirty hours I have never seen that before. Thanks!!

 

[mikeyj350]

I believe this is indicative of a failed mechanical pump diaphragm? If you run the boost pump with the mixture in cutoff (and throttle anywhere) I don't believe any fuel should be flowing at all unless you have a return system.

 

[rvbuilder2002]

Throttle 2/3, mixture cutoff, boost pump on and I get quite a bit of fuel out of the fuel pump from the overflow line onto the floor.

Is this normal?

No.

It is an indication that there is a failure of at least one of the fuel pump diaphragms.

 

[JDanno]

Thanks! That's what I suspected but with only thirty hours ??!!

 

[BillL]

Thanks! That's what I suspected but with only thirty hours ??!!

Just observationally, yes. There are been several reported here in the last year.