WTF! Doing the owner assist annual and all is going like butter UNTIL we found a legitimate fuel selector leak on my 1956 C172 square tail. Did they put the fuel selector in before the outer skin was put on or before the the floor metal was installed. Many gymnastics before the two bolts (and nuts) could be removed to get at the valve out. About $26.50 for the rebuild kit and when I asked about a rebuilt valve I stopped listening at "One Thousand and ........" Anyone else have to do one of these? How the heck do you get the nuts back on to the bottom of the mounting bolts? Probably the same process as a 170B I'd guess.

Frank

Oh man you are right, those do suck! I did my selector on my 56 172 on the ramp at Boeing Field. I was lucky no one saw me doing it because i spilled many gallons all over the nice FBO's ramp before i could get the caps on.
It has been so long but i remember some how putting the bolts in with the nuts in top... maybe tape them in place untill you can get the nuts started or tape the nuts on and do it that way...
While you have it out remove the drain plug and install a quick drain!

I did that myself a few years ago, twice because it still leaked after the first "rebuild kit". Same year, same model, same pain in the rear end. I ended up taping the nuts to the end of an open-end-wrench to hold them in place while I started the bolts. When the bolts were tight I pulled the wrench out and the tape is still there, it won't hurt anything. like the previous post, spilled gas, scraped knuckles, and impolite language are standard for that job.

that one's a bitch.

pretty much need 2 people to get it in out.

make a little nutplate thingy to put it back together. 2 ea MS21059L3 nutplates or similar riveted to a small piece of alu so you can turn the bolts from the top without holding the nuts from the bottom. The next guy that has to pull the thing will thank you. Ill post a pic if I can find it.

also as you reassemble the valve, a little bit of fuel lube can be just sticky enough to keep the little balls in place as you put the valve back together.