fuel filter microns for older cummins and cat engines

[coastlogger]

Wonder what microns these 3408b and L10 and Big cam 400 trucks need? Im having some issues with 2 micron "sm2020 primary filters plugging up quickly. Next step up is a 10 micron. The truck giving me grief at present has an 1987 L10 cummins and the Racor primary separator filter is the only filter in the system. Its not liking the 2 micron after only a few hours I wonder what itd hurt to put a 10 micron in its place. I think its the filter thats plugging although it might be a suction leak I guess.When I start it up cold after sitting it wants to die after a few mins idle. I pull th top off Racor and it a
has very little fuel in it. So I replace element,fill up filter and its good again. I take the old filter,put my thumb in the bottom hole and fill it up with diesel,almost no fuel comes out thru the paper element.. Try this with a new one and fuel pours out of the paper. Sound like a good test or am I missing something? thx for any input

 

[petepilot]

Wonder what microns these 3408b and L10 and Big cam 400 trucks need? Im having some issues with 2 micron "sm2020 primary filters plugging up quickly. Next step up is a 10 micron. The truck giving me grief at present has an 1987 L10 cummins and the Racor primary separator filter is the only filter in the system. Its not liking the 2 micron after only a few hours I wonder what itd hurt to put a 10 micron in its place. I think its the filter thats plugging although it might be a suction leak I guess.When I start it up cold after sitting it wants to die after a few mins idle. I pull th top off Racor and it a
has very little fuel in it. So I replace element,fill up filter and its good again. I take the old filter,put my thumb in the bottom hole and fill it up with diesel,almost no fuel comes out thru the paper element.. Try this with a new one and fuel pours out of the paper. Sound like a good test or am I missing something? thx for any input

my guess would be some really old dirty fuel

 

[Nige]

my guess would be some really old dirty fuel

I think if you pulled the drain plug out of the bottom of the fuel tank you might just be surprised what falls out.

 

[JLarson]

I've got an L10 truck we've been working on that had been sitting and that was one of the first things on the hit list, drain and flush mystery goo from tank and throw filters. People never tighten filler caps, there may not even be a gasket anymore and all sorts of stuff ends up in there.

 

[coastlogger]

After posting I went out and did some more research. I now believe my issue is air getting into system. when I pulled the lid off filter after only sitting for 24 hours the fuel level was down around the bottom of element. And it would not start either. New filter yesterday.,one hour use. Tank is clean. Will do some more research. I wonder how that all works. I dont think the Racor 1000 has a check valve(not sure about this) so Id guess any air leak on the engine side would allow air in and fuel would run back to tank.Does this sound right?

 

[Coaldust]

Probably need a secondary filter on that L10. Maybe a FB1311 Baldwin filter base and a Cat 1R-0750 2-micron filter. Then switch your Racor to a 30 micron element.

Somewhere during this process, figure out where all the contamination is coming from.

 

[Coaldust]

For sure, there could be a leak on the suction side creating a drain back issue. Old hoses, cracked copper flare fitting, dried-up o-rings. A good visual inspection might find it. The Racor does not have a check valve built into it.

 

[Hallback]

Clean out that tank

 

[Hallback]

These are from the 4-53 in my line horse!

 

[Coaldust]

Oh’ my.

 

[John C.]

Pretty normal for something that has sat for a long time, or not been maintained. It is nice to find that kind of stuff when the engine isn't running well, or at all.

 

[coastlogger]

seem to have solved issue it was a leak around t handle on top of filter. thanks for good info. There is no priming pump in this system. Wonder what stand alone priming pumps are suitable for this?