Service Manual User Manual

HYDRAULIC SERVICE BRAKES
To actuate the service brakes, two different circuits
are used. One uses system hydraulic oil, and the
other uses brake fluid.
The hydraulic oil circuit consists of the pilot pump
(A), the pilot relief valve (B). a one-way check valve
(C), which prevents any back-up of oil. A pressure
switch sender (D) to activate the dash light, an
accumulator (E) which contains a nitrogen pre-
charge, and a booster brake valve (F).
Downward pressure on the brake pedal (G)
activates the booster and a combination of foot
power and hydraulic power from the booster exerts
increased pressure to activate the master brake
cylinder (H).
The brake fluid circuit takes over at this point.
Brake fluid from the reservoir(J) flows to the master
cylinder and continues on to the Mico Brake
Control Valve (K). From here, the fluid is routed to
both front wheel brake cylinders (L).
The Mico Brake Lock is for short term use, such as
when working on a slope. The Mico Brake Lock
Lever (K) is located to the left of the operator’s seat.
The brakes must be pressurized by foot pedal before
setting Mico Lock Brake Lever. The brake fluid
reservoir (J) is located behind the cab, under the
valve cover.
GRADALL LOED MATERIALS HANDLER 534B SYSTEM OPERATION
The operator can actuate the mechanical parking brake
by pulling back on the floor mounted lever. A cable is
connected to the caliper type of disc brake which is
mounted between the front axle and the drive shaft. The
caliper pads open or close on the disc in the drive line.
Brake adjustment is made by adjusting cable end nuts,
or by turning knob on parking brake lever.
MECHANICAL PARKING BRAKE
7