Leaking Primary Fuel Filter

[Thomas P Brady]

I have swapped the primary engine mounted fuel filter twice and it still seeps a small amount of fuel. It does not seep fuel at first, but after about 6-8 hours of operation, a small amount fuel will leak out around the seal. It’s is hardly enough to stain a paper towel, but if you put your finger on the bottom of the filter it comes back with diesel fuel on it. There are no issues with the engine performance even at WOT. Any suggestions on how to stop this small fuel seep? (I am using NAPA filters).

Tom

Topic

[David Wesner]

make sure a rubber gasket didn’t stick to the underside of the housing when you removed one. I’ve seen this before on oil filters, would imagine it can happen with fuel filters as well.

D

[Rob Schepis]

You’re using filters with or without a bottom drain?

[Thomas P Brady]

Rob,

I have inspected and cleaned the mating surface and put a thin layer of oil on the gasket before installing. I have used Fleetguard filters and the last one didn’t leak. I plan to order a Fleetguard in the near future and swap it again. The strange thing it will run for a day or (6-8 hrs) with no leaks and then the next time I run it starts seeping fuel.

Tom

[Rob Schepis]

The engine mounted filter is referred to as your “last chance” filter. The “primary” is your off-engine filtration – Racor, SMXDD, etc.

How are you installing the filter? — Wet the gasket with clean fuel and “hand tight” ? No filter wrench or pliers on install, just real tight by hand with a clean filter and dry hands (no slippage)

Have you checked the mating surface on the underside of the filter head to make sure it is all smooth?

Did you ever use Fleetguard FF5285 or FS1280 and have this happen or have you been always using NAPA filters?

[Author]

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