CONTROL GP-HANDLE 2851134 - Caterpillar

Illustration 1 g01278746
(1) Main Control Valve (2) Hoist Cylinders (3) Hoist Control Valve (4) Metering Pump (5) Steering Cylinders (6) Pressure Switch (7) Electric Drive Pump (8) Piston Pump (Steering and Hoist) (9) Piston Pump (Brake, Hoist and Fan) (10) Service Brakes for the Rear Axles 725 (B1L564-Up) and 730 (B1M1-Up) (11) Service Brakes for the Rear Axle 725 (B1L1-563) (12) Fan Motor (13) Service Brakes for the Front Axle (14) Brake Control Valve (15) Accumulator (Parking Brake) (16) Accumulator (Rear Service Brakes) (17) Accumulator (Front Service Brakes) (18) Parking BrakeThe tank contains oil for the following machine systems: Steering system, hoist system, brake system and fan drive system. Return line filters are located inside the tank.Piston pump (8) is a variable displacement pump. The piston pump, which is driven by the engine, supplies oil to the steering system and the hoist system. The output of the piston pump is controlled by load sensing pressure.Piston pump (9) is a variable displacement pump. The piston pump, which is driven by the engine, supplies oil to the braking system, the fan drive system and the hoist system. The output of the piston pump is controlled by load sensing pressure.Both piston pumps are connected to main control valve (1) and the main control valve controls the oil flow to all of the machine systems that are mentioned above. The main control valve ensures that the steering system receives priority flow from piston pump (8). The main control valve also ensures that the braking system receives priority flow from piston pump (9) .The steering system is operated by the steering wheel which is connected to metering pump (4). The metering pump delivers oil to the steering cylinders in order to articulate the machine.The braking system is operated by the brake pedal which is connected to brake control valve (14). The brake control valve allows pressure from accumulator (17) to be transmitted to service brakes (13) for the front axle. The brake control valve allows pressure from accumulator (16) to be transmitted to service brakes (11) or to service brakes (12) for the rear frame depending on the configuration of the rear service brakes.Parking brake (18) is disengaged by pressure within accumulator (15) when the machine is running. The parking brake is engaged by spring force when the engine is shut off or when the parking brake control is moved to the ENGAGED position by the operator.The hoist system is operated by the hoist control