TUBE AS 8W9003 - Caterpillar

Illustration 1 g03477546
Location of the Brake Accumulators for the Service Brakes (A) Accumulators for front service brakes. (B) Accumulators for rear service brakes.The accumulators for both the front and the rear service brakes are located behind the ladder on the right side of the machine. The accumulators are mounted in a vertical position in the service center on the right side of the machine. The accumulators for the front service brakes (A) are positioned on the right. The accumulators for the rear service brakes (B) are positioned on the left.
Illustration 2 g03577503
(1) Nitrogen charging valve. (2) Chamber for the nitrogen gas. (3) Piston. (4) Pressure oil chamber. (5) Accumulator. (6) Outlet to service brake control valve.The four accumulators for the service brakes have piston (3), which is sealed. The piston moves back and forth inside the bore of each accumulator. The chamber for nitrogen gas (2) contains a charge of approximately 6890 kPa (1000 psi) of dry nitrogen gas. The dry nitrogen gas is put into the accumulator through nitrogen charging valve (1) .Oil from the accumulator charging valve flows through outlet (6). The oil then enters pressure oil chamber (4). The oil then pushes piston (3) causing the dry nitrogen gas to compress. When the pressure in the accumulator reaches the cutout pressure, the supply of oil is stopped by the accumulator charging valve.When a brake pedal is pushed, oil from chamber (4) flows outward through outlet (6). This oil flows to the service brake control valve and the oil then applies the service brakes.