The Cessna 120-140 Association Forum

During the annual on our C140A, we found the fuel selector is seeping fuel. From the parts listing, I can't tell if there's an o-ring that can be replaced or something else.

Does anyone have experience in rebuilding these fuel selectors or can give me some advice on if it is rebuildable and if complicated, who might be a good lead for rebuilding it.
Thanks
Ed
806-535-

Hello Ed,
Fuel valve utilized in the 140A is not complicated at all. There is a packing, p/n 0413020-4 (#17 in the parts book) on the valve shaft (#27). If memory serves me correctly an MS29513-109 o-ring is utilized as a replacement.

In order to replace the packing/o-ring do the following
(1) drain the fuel tanks
(2) remove the selector handle (#26).
(3) remove the bracket (#37) to gain access the center nut on the top of the valve.
(4) place some absorbent rags under the valve to catch any fuel that leaks out when the top is removed.

Be careful when removing the nut to gain access to the packing, there’s a small cup (#18) being pushed upward by a spring (#19) on the shaft. That spring pushes up on the packing/o-ring to make a seal where the shaft comes out of the top of the nut.

Take a look at this also https://www.cessna120140.com/Forum2018/ ... f=7&t=2266

Does anybody have a source for the MS29513-109 o-ring? Textron claims to have them in stock but I don't have an account with them. None of the other suppliers I normally use even have them in their catalogs, let alone available.

I can find M83248/1-109, but I'm not sure if those are compatible or not. It looks like the MCM83248 o-rings are what McFarlane uses in their fuel selector rebuild kits so maybe?

Also just want to say what a great help this website has been for me. I own a 1948 170 so a lot of 120/140 information applies to my plane as well.

Try EMC AEROSPACE, INC. in North Miami Beach, Florida or VERTICAL PARTS INC. in Augusta, Kansas.

I've never dealt with either of them, but both report stock.