fuel pump question

The fuel in my fuel filter appears to drain back into the pump when the engine is not running. Is this normal or is it a sign that the mechanical pump is getting old and should be replaced?

 

Mine does the same thing and it has an electric pump that the PO put on.:?

 

My Lhead had the same problem. I rebuilt the carb, and haven't had it since.

 

Diaphragm type fuel pumps have a built in check valve, otherwise they would not be able to build pressure. The pump should be able to hold residual pressure for quite a long time. Mine will hold for at least 3 hours or more. When mine losses the ability to hold pressure, I remove the lines and blow air through it in the direction of fuel flow and it cleans the junk holding the check valve open and the pump once again holds pressure.