RADIATOR GP 3898964 - Caterpillar

Illustration 1 g01128756
(1) Line (2) Inlet (3) AccumulatorThe accumulator stores pilot pressure oil for use at the swing control valve and the main control valves. During some operations, the pilot system needs more oil because there is insufficient flow from the pilot pump. Accumulator (3) will provide pilot pressure oil to the pilot system when the pilot pump flow is inadequate. Insufficient supply of pilot oil flow to the pilot system may be caused by the following two reasons:
Implements are lowered while the engine is stopped and oil supply to the main control valves is stopped.
Combined operationsIn accumulator (3), the gas chamber is surrounded by a bladder. The gas chamber is filled with nitrogen gas. Pilot oil in line (1) enters the pressure oil chamber from inlet (2). The pilot oil acts against the bladder and the nitrogen gas in the gas chamber is compressed. A check valve prevents a backflow of the stored oil in the accumulator. The stored oil is used only for operating the stem of the control valve.