4-22. AIR SYSTEM - Continued
4-22.8 Service Brake Valve - Continued
Two maintenance kits are available for the valve. If the valve pistons and other sliding parts show major
wear, replace whole internal assembly using the major repair kit. If parts are not badly worn, replace only
those parts in the minor repair kit. Instructions below are for the minor repair kit.
Before assembly lubricate all O-rings, bores, and mating surfaces with petroleum jelly (item 21, Appendix
Install new No 2 circuit inlet/exhaust assembly (1) in upper static piston (13), making certain retaining ring
(17) is engaged in groove of upper static piston bore.
Install new O-rings (2 and 3) on upper static piston (13).
Install new No 1 circuit inlet/exhaust assembly (4) in lower static piston (24) making certain retaining ring
(20) is engaged in groove of lower static piston bore.