COVER-VALVE MECHANISM 2784692 - Caterpillar

Illustration 1 g00903236
Location of Accumulator Charging ValveThe accumulator charging valve is located on the right side of the hydraulic oil tank in the engine compartment.
Illustration 2 g00902467
Port Locations for the Accumulator Charging Valve (1) Load sensing port. (2) Tank port. (3) Accumulator port (front service brakes). (4) Accumulator port (rear service brakes). (5) Pressure switch port. (6) Pressure inlet from brake priority valve.Hydraulic oil flows from the priority flow control valve to the accumulator charging valve. The accumulator charging valve maintains the pressure in the accumulators at a constant range while the engine is running.The inverse shuttle section of the accumulator charging valve senses the lower pressure of the two accumulator pressures. The oil then flows from the inverse shuttle section of the accumulator charging valve to the brake accumulator pressure switch. A spool in the accumulator charging valve then moves in order to allow the hydraulic oil to flow to one accumulator or to both accumulators.Note: The brake accumulator pressure switch alerts the operator of low brake oil pressure in the service brake system.The accumulator charging valve also sends oil to the tandem brake control valve. The tandem brake control valve is used to actuate the service brakes.The control section of the accumulator charging valve sends a pilot signal to the pressure compensated load sensing pump. The pilot signal only occurs when additional oil is required in the service brake system. This allows the piston pump to supply oil to the steering and implement systems when there is no demand for hydraulic oil in the service brake system.