PISTON 1K0188 - Caterpillar

Illustration 1 g00909196
Hydraulic Schematic for the Brake System (1) Front service brakes (2) Wires to the transmission electronic control module (3) Left brake pedal (4) Wires to stop lamps (5) Right brake pedal (6) Service brake control valve (7) Accumulator for the front service brakes (8) Accumulator for the rear service brakes (9) Parking brake (10) Parking brake actuator (11) Rear service brakes (12) Accumulator charging valve (13) Parking brake pressure switch (14) Line to the implement circuit, pilot circuit, and steering circuit (15) Brake oil pressure switch (16) Breaker relief valve (17) Parking brake control valve (18) Pilot/brake pump (19) Implement pump (20) Steering pump (21) Hydraulic oil tank (22) Implement and pilot/brake pump (23) To filtration circuit (AA) Pressure tap for the rear service brakes (BB) Pressure tap for the front service brakes (CC) Pressure tap for the service brake accumulators
Illustration 2 g00294076
Left Side View of the Machine (1) Front service brakes. (7) Accumulator for the front service brakes. (8) Accumulator for the rear service brakes. (11) Rear service brakes. (12) Accumulator charging valve. (13) Parking brake pressure switch. (15) Brake oil pressure switch. (17) Parking brake control valve. (CC) Pressure tap for the brake accumulators.
Illustration 3 g00294077
Right Side View of the Machine (6) Service brake control valve. (9) Parking brake. (10) Parking brake actuator. (16) Breaker relief valve. (18) Pilot/brake pump. (19) Implement pump. (20) Steering pump. (21) Hydraulic oil tank. (AA) Pressure tap for the rear service brakes. (BB) Pressure tap for the front service brakes. The implement and pilot/brake pump (22) are connected in tandem by a common shaft. The two vane pumps are mounted in tandem on steering pump (20). Pilot/brake pump (18) and implement pump (19) share a common inlet port from hydraulic oil tank (21), but each pump has a separate outlet port.Pilot/brake pump (18) is a vane pump that supplies the hydraulic oil that is required to operate the brake system. Pump (18) also provides the pilot oil for the implement circuit.Oil flows from pilot/brake pump (18) to brake accumulator charging valve (12). Accumulator charging valve (12) includes the following components. A pressure relief valve, a charge control, a flow control orifice, a spool for cut-in and cut out pressure and an inverse shuttle valve.Accumulator charging valve (12) controls the flow of oil from pilot/brake pump (18) to brake accumulators (7) and (8). A pressure relief valve that is located in accumulator charging valve (12) limits the oil pressure that flows from pilot/brake pump (18) .Oil then flows through an inverse shuttle valve that is located in brake accumulator charging valve (12). The oil then flows to brake accumulators (7) and (8). A third port in the inverse shuttle valve connects to switch (15). Switch (15) monitors the oil pressure in the two brake accumulators. If the oil pressure in either brake accumulator drops below the minimum threshold, switch (15) actuates.Brake accumulators (7) and (8) contain a precharge of dry nitrogen. When oil flows into an accumulator, the pressure oil moves the