Gradall 534B (9103-1148) Operation Manual - Manual (Page 10)

The brake system furnished on The handler includes
a service brake, parking brake and Mico lock.
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:
As illustrated, the three functions occur in sequence
as service brake/inching pedal is depressed from top
to bottom of stroke.
BRAKE SYSTEM
General
It disconnects front drive axle from
transmission.
It controls hydraulic flow to rear axle drive
motors (hydraulic flow regulates speed).
It applies service brake.
1.
2.
3.
Service Brakes
The power-assisted hydraulic service brake is
applied only to front wheels of handler.
When the service brake/inching pedal is depressed
far enough to actuate the service brake master
cylinder, brake fluid flows to wheel cylinders to
apply service brake. At the same time, pilot pressure
is applied to a piston within master cylinder to
intensify (boost) pressure to wheel cylinders.
Practice inching/braking in a safe, open
area until you are thoroughly familiar with
response of machine to pedal travel.
9
Mico Lock
The Mico Lock can be used to reduce operator
fatigue by temporarily locking a service brake
application on using a hand lever rather than holding
brake pedal.
Though it is possible to stop the handler
without the power assist feature, very
heavy foot pressure is required and
stopping distance will be significantly
greater.
To Release Mico Lock
Release Mico Lock by pushing lever forward to
release position (lever horizontal).
Never use Mico Lock as a parking brake.
The brake application will bleed off after a
short time and allow the machine to roll.
To Apply Mico Lock
Check to be sure Mico Lock lever is pushed
forward to release position (lever horizontal).
Depress service brake pedal fully and hold.
Pull Mico Lock lever back to lock position (lever
vertical) and then release brake pedal.
1.
2.
3.
contined...