a727 no third gear

when I aircheck the clutches in the pump when sitting in a vise they seem to seal up really well, then when I put them in the tranny and aircheck I hear a lot of air coming from I think the front clutch, somewhere in that area
Well then u have ur answer. The inner seal on the front drum isn’t sealing very well if u hear hissing while using 30 psi. Check the valve body over real good or replace it as gas been mentioned. Kim