Gradall 534B-9 Operation Manual - Manual (Page 16)

BRAKE SYSTEM
General
The brake system furnished on the handler includes a
service brake and parking brake.
Because service braking and “inching” (slow travel)
functions overlap, some features of inching will be
discussed here. Refer to Drive Train Section for
additional information on inching travel.
Inching Travel
Overlap between service braking and inching occurs
because the same foot pedal controls both functions,
and also because both functions control travel speed.
However, the methods of controlling travel speed are
quite different: service braking involves a controlled
stopping force applied to the front wheels while
inching involves a controlled driving force applied to
the rear wheels.
The service brake/inching pedal has three separate
functions
It disconnects front drive axle from transmission.
It controls hydraulic flow to rear axle drive motors
( h y d r a u l i c f l o w r e g u l a t e s s p e e d ) .
I t a p p l i e s s e r v i c e b r a k e .
Service Brakes
The service brake is applied to the front wheels of the
handler.
Oil for the brakes comes from the pilot circuit pump,
thru an accumulator charging valve and the accumu-
lator. When the service brake/inching pedal is
depressed far enough to actuate the brake valve, the
hydraulic oil flows to the wet disc brakes in both
front wheel hubs. The pressure compresses the brake
discs .
As illustrated, the three functions occur in sequence
as service brake/inching pedal is depressed from top
to bottom of stroke.
Practice inching/braking in a safe, open
area until you are thoroughly familiar with
response of machine to pedal travel.
1 5
Parking Brakes
Because the parking brake is spring-applied and
hydraulically released,the engine must be running to
provide pressure to release parking brake.
On early units the parking brake is applied and
released by a control valve knob located to the left of
the operator’s seat. Raise knob to apply brake and push
knob down to release brake.
On recent units the parking brake is applied and
released by a switch located on the dashboard. Depress
right side of switch to apply brake and depress left side
of switch to release brake.
Always be certain to apply parking brake, stop engine
and remove key from ignition switch before leaving
operator ’s cab.
1.
2.
3.