794 AC Off-Highway Truck Systems Caterpillar

Illustration 1	g06411992
(1) Dynamic retarder pedal (2) Load brake switch (3) Load brake shuttle (4) Rear brake drag pressure switch (5) Front brake drag pressure switch (6) Supply brake accumulator (7) Rear brake accumulator (8) Electronic control module (Chassis) (9) Electronic control module (Brake) (10) Front Auto apply shuttle (11) Rear Auto apply shuttle (12) Brake control valve (Dual brake valve) (13) Control manifold (Brake) (14) Secondary brake pedal (28) Rear Proportional auto apply brake valve (29) Front Proportional auto apply brake valve

Illustration 2	g06338694
(15) Front brake group (16) Piston pump (Steering) (17) Rear brake cooling manifold (18) Rear slack adjuster (19) Rear brake group (20) Rear brake oil temperature sensor (21) Front brake accumulator (22) Front slack adjuster (23) Front brake oil temperature sensor (24) Brake cooling supply manifold (25) Check valve (26) Brake cooling return manifold (27) Park brake relay valve

The brake system is electronically controlled through the Brake Electronic Control Module (ECM) and the Chassis Electronic Control Module (ECM). The steering pump supplies oil pressure to charge the accumulators. The braking system consists of service brakes, dynamic retarder control brake, load brake, and parking brake. The front and rear service brakes are wet type brakes, which are hydraulically engaged and released by spring force. The front and rear park brakes consist of wet brakes in the wheel assemblies. The parking brakes are wet brakes that are spring applied and hydraulically released. The service brakes are used to stop the truck after the electric drive system retarder pedal has slowed the truck to less than approximately 5 km/h (3 mph). The service brakes have the capability of stopping a fully loaded truck on a 10% grade in emergencies. The service brake can be applied using the foot brake pedal. The load brake switch actuates a solenoid that applies only the rear service brakes. The load brake is designed for only dumping or loading. Do not apply the parking brake when dumping or loading. The park brake must be used when the operator is leaving the cab. The park brake is applied by placing the shift control lever into the PARK position. The park brake controls the parking brake on the front and rear wheels.