a odd fuel filter problem

[snowstorm]

this is the first time i have seen this. volvo truck 12 L uses a racor primary filter and filter base. if it sat for a few days it would flutter or stall then run ok. what it turned out to be. the filter base is painted where the gasket seals. some of it was gone along with a tiny bit of corrosion. new filter base and filter purrs like a tom cat

[1270d]

So the corrosion was letting it leak back?  Or was there some pores in the casting of the base?

[snowstorm]

corrosion but not much of it. enough to lift the paint and enough that the filter would not seal but it did not leak fuel. seemed kinka odd that the gasket sealed on a painted surface

[treeslayer2003]

could you have just polished the surface? i had a detroit housing that was porous like 1270 said, drove me nuts for a while.

[Ox]

Gotta remember that sealed diesel systems will leak air while they won't leak fuel.  Molecules are smaller for air.  :laugh: