Late model 4L60E

When I air check the pistons in the input drum I get a hiss from all three. I have taken the input drum apart and I cannot find any problems with the seals...moulded seals by the way.

I bought a new forward, overun, and 3-4 piston. I am still getting the same problem. When air is applied to the 3/4 feed I can hear hissing from the drum. When air is applied to the overun feed and the piston is at its maximum travel air leaks from all sides. Any ideas?

 

a small amount of air is normal, remember there will be fluid doing the job and not air, air can fit through smaller gaps than atf fluid