Small Engines (Lawn Mowers, etc.): fuel flow, fuel hoses, vent cap

Question
i have a garden tractor w/a onan20hp,the fuel filter only fills about a 1/8 inch,when i saw that i made sure gascap vent cap was clean ,replaced all the fuel hoses and eventually ended up replaceing the fuel pump(including the pulse hose).while i was there i fixed an intake leak,the tractor no longer surges w/intake fixed however the fuel filter still does not fill,i seem to remember it used to,am i wrong is it getting what it needs,i did not touch carb but it runs decent,what else might be wrong?

Answer
Did you use an Onan filter and the correct, exact Onan fuel line lenghts?
I've seen this happen before, but I used aftermarket parts instead of Original Equipment Manufactured (OEM) parts.  As long as the engine runs smooth you shouldn't have any trouble.
Let me know what parts you used.
Eric