HOUSING AS-FRONT 1616648 - Caterpillar

Illustration 1 g03872715
Pilot Manifold
(1) Pilot accumulator
Illustration 2 g02328013
(A) Membrane
(B) Pressure vessel
(C) Gas chamber
(D) Oil chamber The accumulator has the following three functions:
Keep the pilot pressure constant and balances pressure variations.
Store energy.
Release the energy to the system.Pilot accumulator (1) provides oil for the following functions:
Lowering the boom and the stick in the event of loss of pilot system pressure
Lowering the boom and the stick after stopping the enginePilot accumulator (1) stores pressurized hydraulic oil in oil chamber (D) by taking advantage of the compressibility of nitrogen gas in gas chamber (C). A check valve will seal the oil inlet when membrane (A) is fully extended.The pilot pump oil goes through the inlet port and into pressure vessel (B). Entering oil acts against the gas that is in the chamber through the bladder in order to maintain oil pressure. The factory filled nitrogen charged accumulators must be replaced if the accumulators fail.