SCREEN ASSEM. 6P6496 - Caterpillar

Illustration 1 g00879029
Illustration 2 g00879249
Components of the Service Brake (1) Sun gear. (2) Dowel. (3) Spring. (4) Ring gear. (5) Planetary gear. (6) Axle housing. (7) Carrier. (8) Piston. (9) Plate. (10) Friction disc. (11) Plate. (12) Axle shaft.Note: The 814F Series 2 Wheel Dozer is equipped with standard service brakes on the fixed axle (front) and the oscillating axle (rear). The 815F Series 2 Soil Compactor and the 816F Series 2 Landfill Compactor are equipped with standard service brakes on the fixed axle (front).The service brakes are located in the axle housing on both sides of the differential. The brakes are activated by hydraulic oil pressure. The heat that is created by the friction within the brakes is removed by the oil in the axle housing.Each service brake consists of piston (8), plate (9), friction disc (10), plate (11), dowels (2), and springs (3). Friction disc (10) is splined on the inside diameter. The splines mesh with splines on sun gear (1). The friction disc and the sun gear turn with the axle shaft.Plate (9) and plate (11) are fastened to axle housing (4) and the differential housing with three dowels (2). The plates are able to slide on the dowels, but the plates do not rotate. Springs (3) force piston (8) to retract when the brake is not engaged.Carrier (7) is fastened to axle shaft (12) by splines. The axle turns with the carrier. As sun gear (1) is driven by the differential, planetary gears are forced to revolve around the inside of stationary ring gear (4). The movement of planetary gears (5) around ring gear (4) causes carrier (7) and axle shaft (12) to rotate. This transfers power to the rim and the wheel.The service brakes can be actuated by either the left brake pedal or by the right brake pedal. When the service brakes are applied, pressurized oil flows from the service brake control valve into a cavity behind piston (8). The oil forces the piston against the stack of plate (9), plate (11), and friction disc (10). This causes friction between the plates and the friction disc. The friction causes rotation of the axle shaft to slow down. When more force is applied to the brake pedal, the pressure on the stack of plates and friction disc will increase. This causes an increase in the amount of friction in the brake which will cause the axle shaft to stop rotating.Excessive heat that is created by the friction in the brakes can make the service brakes ineffective. Grooves are cut into both sides of friction disc (10). These grooves permit the circulation of oil in the axle housing between the plates and the friction disc. The oil cools the brake components. If the groove depth on the friction discs is not adequate, the service brakes can overheat.ReferenceFor more information on the requirements for the depth of the grooves on the friction discs, refer to the Service Manual module Testing and Adjusting, "Service Brake Discs - Check"