Caging the brakes releases the brakes and prevents operation of semitrailer
braking system. When brakes have been caged, semitrailer should only be moved
under emergency circumstances and then only with extreme caution and at
speeds not greater than 10 mph. Failure to comply may result in death or injury to
personnel. Seek medical attention in the event of an injury.
Spring inside brake chamber is under very high pressure. DO NOT loosen or
remove any nuts or bolts from brake chamber except caging bolt and its
associated hardware. Failure to comply may result in death or injury to personnel.
Seek medical attention in the event of an injury.
This procedure is used to manually release the brakes in the event that the air supply to
the semitrailer has been lost or interrupted. This procedure should be performed only
under extreme circumstances when the semitrailer must be moved.
Place blocks under semitrailer wheels to prevent semitrailer from rolling during procedure.
Remove dust cover (Figure 21, Item 3) from caging bolt keyhole (Figure 21, Item 2) in center of spring brake
chamber (Figure 21, Item 4).
If the inside of the spring brake chamber is clogged with mud, sand, or dirt, do not proceed
with the caging procedure unless the chamber can be cleared. Notify Field Maintenance if
chamber cannot be cleared.
Visually inspect the inside of the spring brake chamber (Figure 21, Item 4) for mud, sand, or dirt.
Remove nut (Figure 21, Item 5), washer (Figure 21, Item 6), and caging bolt (Figure 21, Item 1) from side of
the spring brake chamber (Figure 21, Item 4) being caged.
Figure 21. Caging the Brakes.