Fuel Selector Valve

[Skymaster337B]

Has anyone ever rebuilt a fuel selector valve? Specifically, do the checkballs usually wear out, and are those checkballs easy (and cheap) to get from Cessna?

Any other hints would be appreciated.

[Guy Paris]

Check with Don Nieser.. guy paris

Don Nieser
405-722-4079
405-503-4686 cell
nieser.02.337parts@juno.com

[Richard]

They are not hard to rebuild, but kind of a pain to remove. What I found most troubling on the unit is the cork gasket. They tend to shrink over time and can start to leak.

If you are experiencing "sticky" valve switching, most times the check balls can be cleaned and re-lubed with no appreciable wear on the surface. Cable friction is also a culprit of those symptoms.

We pulled the valves and found the majority of the resistance due to dirty solid core wires going to the valve. The cables were removed, cleaned, and re-installed. Now, they are like butter.

[Skymaster337B]

The problem I'm having is the valve sweats. I tried to tighten the screws on top but it's almost impossible because my hands are too big to get around the fuel lines. It seems like there should be an access panel on top of the wing, but of course there's not, and it's a structual panel.

I found a small screwdriver at Sears, it's only a 1/2" tall, but the handle is a very round wheel that I can use with just my fingers. I'll try that.

But if I have to remove the valve from the wing (to replace the cork seal) do you have any tips/tricks to pull it out?

[KyleTownsend]

I have a T337G model, and we recently noticed that fuel would still drain from the front engine fuel sump with the front engine fuel valve closed. Of course, we immediately suspected the valve. However, tapping on the check-valve for the fuel return line from the front engine back to the tank quickly revealed that this was the actual culprit. Might be something you want to check.

Of course, the fuel valve setup is somewhat different on the B models vs. my T337G, so these comments might not apply to your situation.

[Skymaster337B]

That's some good info about the fuel strainer. I will certainly put that in my shop notes. However my actual fuel valve is what's acting up. So I might have to pull it out and rebuild it; however, there is no easy way to do that because of the tight space in the wing.

Does anyone know of a short cut to remove the fuel valve from the wing?

Skymaster337B, Did you ever sort out your fuel selector problem?

[Skymaster337B]

No, do you have a 411 on a gasket part number?

[hharney]

Item 10, is this the gasket (packing) you are looking for?
M83248/2-906
http://www.cessnaparts.com/search.cfm

[Skymaster337B]

Thanks for asking. But item #10 is an o-ring, around a b-nut. The gasket I'm talking about is a cork type gasket that seals the entire wing-mounted fuel selector valve body. Unfortunately the parts manual only lists it as a complete assembly. I new assembly was $15K the last time I checked...not going to happen. I will make my own gasket if I have to, but always like getting new parts if they are available...plus the maintenance down time is quicker.