Parking Brake Operation; Parking; Anti-Lock Brake System (Abs) - Mack Granite GU Series Operator's Handbook Manual

Parking Brake Operation

The parking brakes can be applied and released from the cab, using the
hand-operated push/pull control valve with the yellow diamond knob.
In the event of a significant air pressure loss in both the air brake systems,
the spring brake air chambers will be automatically exhausted (applying the
brakes). The parking brakes will remain applied until enough pressure is
available to recompress the springs.

Parking

WARNING
• NEVER use the trailer parking brake system alone.
• NEVER use the tractor parking brake system alone.
• ALWAYS use the tractor and trailer parking brake systems together.
• ALWAYS apply the parking brakes when parking and make sure the parking
brakes are holding the vehicle from moving before leaving the driver's seat.
• When parking on a grade, use wheel chocks under the rear wheels or turn
the front wheels to the curb. Do not leave diesel engine vehicles in gear; if the
vehicle should move, the engine may start by heat of compression.
• Check brake adjustment frequently to be sure that the brakes will lock and
hold the vehicle when parked.
• Do not use the parking brake to slow or stop the vehicle when in motion,
except in an emergency.
• Do not use hand control valve for parking.

Anti-Lock Brake System (ABS)

Note: Anti-lock brake systems became mandatory in the U.S.A. on all tractors
beginning March 1, 1997; all trucks beginning March 1, 1998, and all trailers
beginning March 1, 2001. Federal regulations require that any tractor/truck with a
trailer air connection built beginning March 1, 2001 must have a data communications
link with the trailer ABS and an indicator lamp located in the cab to alert the driver if
there is a trailer ABS malfunction.
OPERATION 161