TUBE 8N9706 - Caterpillar

Illustration 1 g06077527
Service brake component locations
(1) Axle Housing Group
(2) Planet Carrier
(3) Planet Gear
(4) Sun Gear
(5) Ring Gear
(6) Seal
(7) Ring Seal
(8) Backup Ring
(9) Oil Lines Group
(10) Reaction Piston
(11) Friction Plate
(12) Core
(13) Friction Plate
(14) Reaction Plate
(15) Reaction Dowel
(16) SpringThe service brakes located in front axle housing group (1) are activated by oil. The heat from friction of the brakes is removed by the oil in the axle housing.The service brake consists of the following basic components: piston (10), friction plate (11), friction plate (13), core (12), reaction plate (14), reaction dowel (15), and spring (16).Plate (14) is held stationary. The plates for the piston housing are able to slide on reaction dowels (15). The plates do not rotate. Springs (16) keep piston (10) in the RETRACTED position when the piston is not being used.Friction plate (11) and friction plate (13) have splines on the inside diameter that fit on the splines of sun gear (4). Planetary carrier (2) causes friction plate (11) and friction plate (13) to rotate at the speed of sun gear (4). Grooves are cut into the faces of friction plate (11) and friction plate (13). The grooves allow the passage of cooling oil between the two friction surfaces and between piston (10) and reaction plate (14).Planetary carrier (2) is fastened with splines to the axle shaft. Planetary carrier (2) rotates with the axle shaft.When you push a brake pedal, pressurized oil from the service brake control valve flows through oil lines group (9) and into the passages on the differential housing. The force of the oil behind piston (10) moves the piston against the force of springs (16). The force of the oil pushes friction plate (11) and friction plate (13) against reaction plate (14). The friction slows down sun gear (4), the machines axles, and wheels. The machine can then be brought to a complete stop.When the brake pedal is released, the oil behind piston (10) flows through the oil passage . This oil flows to the service brake control valve. The oil then returns to the hydraulic oil tank. With no oil pressure behind piston (10), springs (16) move the piston to the RETRACTED position and the service brakes are released.The service brakes can be actuated by either the left brake pedal or by the right brake pedal. When the transmission neutralizer override switch is moved to the UNLOCKED position, both of the brake pedals apply the service brakes. However, only the left pedal may be used to neutralize the transmission. When the transmission is neutralized, this neutralization allows the full engine power to be used in the hydraulic system.Reference: For more information on the function of the transmission neutralizer, refer to Systems Operation, "Transmission Neutralizer Override Switch".If the machine loses power, or if the hydraulic pump fails, the service brakes can still be applied. The pressure in the nitrogen charged accumulators for the service brakes allows a minimum of nine applications to the brake pedals. The brake applications will slow the machine enough to