CAGING THE BRAKES (Continued).
The brake chamber contains a spring under high pressure. To prevent personnel
injury or death, never work directly behind the brake chamber. If caging bolt will
not engage properly, the spring may be broken - do not continue caging procedures.
Insert the T-end (8) of the caging bolt into the keyhole (7) in the brake chamber. The T-end
should be inserted into key-way of the metal diaphragm (11) inside the brake chamber. Turn
the caging bolt one quarter turn clockwise until the caging bolt contacts stop inside
Pull on the caging bolt to seat it properly. The caging bolt is properly positioned when it
cannot be removed by pulling straight out.
Place washer (9) and nut (10) onto threaded end of caging bolt (8).
To cage the main spring, tighten the nut (10) on the caging bolt (8). Visually check to ensure
that the service push rod is retracting into the spring brake chamber. This procedure will
compress the brake spring inside the brake chamber and release the brake at the wheel
Do not over-torque the caging bolt assembly [35 ft-lb (47.46 Nm) maximum].
When the spring is fully compressed and the brakes are released, the threaded portion of
the caging bolt should extend 2.5 in. (6.35 cm) to 3 in. (7.62cm) beyond the nut.
Brakes should remain caged until proper maintenance personnel can inspect the brake
Repeat procedures as necessary for remaining wheel positions.
To uncage the brakes release nut (10) on caging bolt (8), return caging
bolt (8), washer (9) and nut (10) to original location on side of brake spring
chamber (4) and close dust cover (3).