Ended up leaving the valve alone. (We got sidelined with more critical issue of flap-trim interconnect cable seizing in its sheath and restricting trim control.) It's on a future project list when can stand risk of long term disabling the valve. But have been concerned about what you experienced. Likewise agree about checking the rigging.

Thanks guys! I will check the rigging and go from there - that is a good idea o verify the easy stuff and go from there. Thanks again!

rebuild fuel selector valve
 

wslade2.
FYI, you CANNOT just replace the original clips with a C clip from a assortment of clips. That would be illegal. I'm not trying to be a know it all but as an A&P I know there are rules in the FARs that prohibit this kind of modifications. If the original clips are not serviceable and hard to come by you may have to buy a serviceable selector valve and replace the whole valve?? Has anyone tried contacting AIRBORNE the original valve manufacturer, for the clips?
Just a thought.
Regards, BILLS

McFarlane
 

Has anyone used McFarlane to rebuild their fuel valves? I spoke with Dave 2 days ago and he told me they can rebuild them now. He said it's mostly labor, but they do fabricate a few pieces. He mentioned somewhere in the $600 range.

We're having some issues and may need a rebuild also.

That is super duper news! McFarlane was on my list.
Tried to call Airborne for parts. They don't exist as they did before. They have been absorbed by parker hannifin.
(check this link: https://semspub.epa.gov/work/05/465914.pdf)
Called Parker Hannifin, pretty big outfit and have not gotten a call back from them. (out due to coronavirus?)
Did call B&S and they think they have one gasket on the shelf but did not want to sell it in case they need it. They said their suppliers have stopped. Then got call from someone else there who wanted me to call yet another person there to see if they have capability to service it. But have not gotten a call back yet.
They also directed me to Ross Aviation parts. Ross reports the valve is superceeded by a 1H12-3 obtainable at a price of $14,000 (yes fourteen thousand). Yingling also has it for $14K and change with a $3000 core charge. To dive deeper in parts, would need a repair manual for the valve listing part numbers for springs/gasket/retaining rings.
Called Quality Aircraft Accessories and they confirmed (again) they do not service this valve.
Called Cox Airparts and they said they were getting out of the fuel valve business.
But the good news is, called Powerpacks Plus. They will repair it. They won't overhaul it, though, and you won't get a part back with paperwork/certificates. But it can be worked on.
I couldn't find anyone to supply parts, retaining rings, springs, gasket.

FYI
Dave owns a Skymaster