SPOOL-SELECTOR 6Y0725 - Caterpillar

Accumulators for the Service Brakes
Illustration 1 g00664132
Location of the Service Brake Accumulators (1) Accumulator for the front axle brakes (2) Accumulator for the center axle brakesThe accumulators that are used for the service brake system are located under the transmission cover on the left hand side of the machine. Accumulator (1) is connected to the brake lines for the front axle brakes. Accumulator (2) is connected to the brake lines for the center axle brakes.The accumulators for the service brakes are charged with dry nitrogen to a pressure of 3100 170 kPa (450 25 psi).
Illustration 2 g00674074
Accumulator for the Service Brakes (1) Nitrogen charging valve (2) Accumulator (3) Outlet to the service brake control valve (4) Pressure oil chamber (5) Piston (6) Chamber for nitrogen gas chargePiston (5) moves up and down inside the bore of accumulator (2). Chamber (6) has a charge of approximately 3100 kPa (450 psi) of dry nitrogen gas. The accumulator is charged with nitrogen through charging valve (1) . Oil enters pressure oil chamber (4) from the brake pump. The oil reaches the pressure oil chamber through outlet port (3). The oil pushes piston (5) upward. The pressure of the oil compresses the nitrogen gas.When the pressure in the accumulator reaches approximately 20340 kPa (2950 psi), the supply of oil is stopped. When the brake pedal is pushed, oil from pressure oil chamber (4) flows out of port (3) to the service brake control valve. This applies the service brakes.Accumulator for the Parking Brake
Illustration 3 g00664133
Location of the Parking Brake AccumulatorThe accumulator for the parking brake system is located under the transmission cover on the left hand side of the machine.The accumulator for the parking brake is charged with dry nitrogen to a pressure of 9650 172 kPa (1400 25 psi).