SUB-SECTION 9D
BRAKE CHAMBERS
Air pressure entering the service brake air inlet will force
MAXIBRAKE CHAMBER 38Q18)
the diaphragm against the push rod assembly, extending the
push rod from the chamber. Since the push rod is con-
DESCRIPTION. A Maxibrake chamber is a combination
nected to a slack adjuster, outward movement of the push
service brake chamber and spring brake, which provides two
rod will rotate the brake cam and apply the brakes, Venting
methods of applying the carrier brakes (see Figure 9D-3).
air pressure from the chamber will retract the push rod,
which in turn rotates the brake cam in the opposite direc-
NOTE
tion, releasing the brakes.
Earlier models of this machine- are equipped with
If the air pressure is vented from the spring chamber, by
Maxibrake chambers on the rear axle only. Current
models have Maxibrake chambers on all rear wheels.
shifting the Maxibrake control valve to the vented position,
either automatically or manually, the power spring will ex-
Service air pressure is supplied to the spring chamber air
pand, forcing the piston outward. Outward movement of
inlet by the Maxibrake control valve. Air pressure at this
the piston, places the neck of the piston against a flange nut
on the end of the push rod. This pushes the push rod out-
inlet will compress the power spring, allowing the chamber
to function as a basic service brake chamber.
ward, rotating the brake cam to apply the brakes.
Figure 9D-3. Maxibrake Chamber 38Q18)
9D-3
