Fuel Selector - Another Item for the Annual

[Guest Anonymous]

I was just going along in cruise after my annual, happy as could be -- until I tried to switch tanks.  I was runing on the right tank at the time, and when I tried to cut over to the left one, the fuel selector handle went as far as off, but no further!

That wasn't gonna work for me, so I went back to the right tank, which with luck still had some fuel in it and changed my destination to my local friendly Mooney Guru.

We pulled out the fuel valve/strainer assembly -- nothing improper in the strainer.  so we drained the tanks, disconnected the fuel lines and pulled out the valve.  The problem was corrosion on the base of the selector shaft - not from the selector, which is stainless, but from the housing assembly.  Apparently, over the years, the dirt and grime from the cockpit floor had found its way into the recess for the fuel selector.  That and some small amounts of water from wet shoes, condensation, whatever, were enough to permit a corrosion build up at the base of the shaft.  The face seal of the selector, and the seals on the tank input lines were all OK, even better that we expected.  A little fine emery cloth, some solvent and some fuel seal  to work on the shaft base and the upper housing assemby were all that was needed to make it like new again.  It now works easy with positive detents for the correct left, off and right positions.

Morale to the story -- if your fuel selector has a little too much resistance, it might be a good idea to take this simple action on the next annual.  Doing it could prevent a need for a fuel selector rebuild, which is a $250 maintenance item according to Lake Aero.  Even more important, it might prevent a few moments of concern if a tank switch won't work, and little or no fuel is in the remaining tank!

RFB

[Flybeech21]

I had this same problem.  My fuel selector stuck in the off position and I had to get a pair of pliers to get it unstuck.  Lucky for me I still had my tool bag in the back seat. 

The procedure you mentioned worked for me as well.  I plan on rebuilding the selector anyway.

[Jerry 5TJ]

Back when I lived in Maryland and had an "E" model, I went cross-country flying one fine winter day, CAVU but cold.

About an hour into the flight I tried to switch tanks. I found that some slush from my shoe had gotten down into that cup in which the fuel selector sits, and at altitude froze solid.   The fuel selector handle was embedded in half an inch of ice, and there was no way to defrost it in the air, and no way to use the 26 gallons of 100LL on one side.    So, I landed at a nearby airport, had the plane put in a heated hanger and it was all dried out the next morning. 

After that I cut a square of carpet and kept it over the selector when the plane was on the ground, so that nothing could fall into that cup.  

[231Pilot]

I flew a C for 6 years.  The fuel selector switch was always very stiff, but turnable.  I made a "T handle" wrench out of PVC plumbing to fit over it so I could turn it easily while in IMC..no ducking or bending over to find and turn the switch when I needed to continue my scan (no auto pilot, only handflying).  With time, it got stiffer and stiffer until it would barely move.  Sent it to Don Maxwell for overhaul and the problem disappeared...easy to turn.  I did continue to use my 12" PVC T wrench for convenience even though I no longer neeced the leverage it provided.

[Guest Anonymous]

Quote: 201Pilot

I flew a C for 6 years.  The fuel selector switch was always very stiff, but turnable.  I made a "T handle" wrench out of PVC plumbing to fit over it so I could turn it easily while in IMC..no ducking or bending over to find and turn the switch when I needed to continue my scan (no auto pilot, only handflying).  With time, it got stiffer and stiffer until it would barely move.  Sent it to Don Maxwell for overhaul and the problem disappeared...easy to turn.  I did continue to use my 12" PVC T wrench for convenience even though I no longer neeced the leverage it provided.