In line fuel filters.

[jon laing]

My mechanic recently installed an in line fuel filter on my stock 1939 -- 85 hp engine between the fuel pump and the carburetor. Ever since then the car has been very hard to start. It acts to me like it is not getting fuel. If the car sits a while I noticed the filter has no fuel in it. It is filled with air. Do I need a check valve between the filter and the pump? Perhaps fuel is draining back thru the fuel pump. That does not seem normal. Perhaps the fuel pump needs a rebuild. Any suggestions will be appreciated. Prior to this it was a very easy starter. Jon Laing