Fuel in the header decreasing with fuel in mains

1,000 thank you's...

Apparently our fuel pumps were used in Buicks and Chevys. Check this out.

www.then-now-auto.com/product/buick-fpa-29/

I still get the gaskets for the AD from Aircraft Spruce, they appear to be higher quality.

I know this is an old post but very relevant to my situation.  What did you use to rebuild the fuel pump?  Part # where purchased,  anything that will help (now begging)  I have the very same issue...  The header tank is emptying faster than it is being refilled and I believe it is the one way valve.  I would like to rebuild the pump and feel safe again on a long flight.  I was on a long xcountry last week and when I landed I had 5 gallons in the wing tanks and about 1 in the header tank.  I have a post currently in the Forum addressing this issue.  Any help is much appreciated... 

Well that's at least somewhere to start looking. Thank you

I had the same problem and we found a loose fitting that connects the fuel line to the input side of the fuel pump. It was sucking some air along with the fuel. After tightening the fitting another turn everything is fine again. I believe that a leaking fuel cover gasket or a failing fuel pump could also be the problem. Again, I'm NOT an expert.......or mechanic.

I have a question to follow up this conversation if anyone knows the answer. I have noticed fluctuations in my header tank this year where it is going up and down but, not consistently. In years past, I cannot recall it moving at all when fuel is in the mains yet. Is this the sign of a failing fuel pump or should I start by checking the fuel pump cover like the issue below?