Gradall G6-42P (91404003_Before 0160004017) Operation Manual - Manual (Page 22)

General
The brake system includes a service brake and a parking brake. Service and
parking brakes are applied through wet disc brake packs located within
axle housing.
Because service braking and “inching” (slow travel) functions overlap, some
features of inching will be discussed here. See “Drive Train” Section, Page
10.0 for additional information on inching travel. (See Figure 3-1 for layout
of controls)
Inching Travel
Overlap between braking and inching occurs because the same pedal controls
both functions; 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. Inching involves a
controlled driving force applied to the driving wheels.
Figure 7-1
Most of the inching travel pedal stroke controls the speed of inching travel. As
the pedal nears the bottom of its stroke, service brakes are engaged.
Service Brakes
The power-assisted service brakes are applied only to wheels of the front axle.
Hydraulic pressure for power-assist feature is provided by a brake circuit.
Depressing service brake/inching travel pedal to braking portion of pedal travel
causes controlled hydraulic pressure to be applied to service brakes. The greater
the pedal travel, the greater the braking force.
If power-assist fails, it will require much greater force on pedal to apply brake
and stopping distance will be greater.
Parking Brakes
The parking brakes are spring-applied and hydraulically-released.
Hydraulic power to release parking brakes is provided by the hydraulic system
and is controlled by the parking brake switch located on the dashboard.
With the engine running and the parking brake switch “Off”, parking brakes are
disengaged. Moving the switch to “On” releases hydraulic pressure to apply the
parking brakes. With switch in “On” position, four-wheel drive is disabled.
BRAKE SYSTEM 7.0
WARNING !
Practice inching/braking in a safe,
open area until you are thoroughly
familiar with handler response.
WARNING !
If power-assist feature should fail
for any reason, it would require
greater effort to apply service
brake.
If power assist fails, stop as soon
as possible. Do not drive the
handler until problem has been
corrected.
WARNING !
Always move parking brake switch
to “On” position before leaving
cab.
Never stop engine while traveling,
all hydraulic pressure will be lost
and parking brake will be fully
applied causing unit to stop
abruptly. A sudden stop could
cause load loss.
NOTE!
In the event of engine or
hydraulic failure, parking
brakes can be released for
towing. See “To Release
Parking Brake”, Page 20.1
SERVICE BRAKE/
INCHING TRAVEL PEDAL
HIGHEST INCHING TRAVEL SPEED
LOWEST INCHING TRAVEL SPEED
SERVICE BRAKING