If you let the air out of your fox float,then take the weight off the sled..........like roll it up on its side, the outer sleeve will unscrew by hand...........desigend that way. Unscew it, slide it down and you are supposed to have an 0z or two of synthetic light weight shock oil in this air chamber to help lubicate the seals on the sliding surface, add a splash, hand tighten the sleeve and air it up. I just use my compressor with regulator set to 50psi for the fronts, then a couple of stokes with a pump for what ever the customers PSI preferance is. So obviously, you should always be able to detect a little oil on this sliding surface. Will be gone in about 500 miles or so, then add more.
Some shock rebuilders don't put the oil back in becasue customers were complaining about oil on their shock body and worried shock was leaking.
If a float leaks, you'll know...........you'll be sitting on the snow.