MARKER 7W3469 - Caterpillar

Illustration 1 g01046624
Service Brake Pedal (Arrows)Depress one of the service brake pedals in order to apply the service brakes for normal braking. Releasing the pedal will release the service brakes. The machine will move if the control lever is in either forward or reverse speed, and the parking brake is not engaged. Machines that are equipped with a creeper will not move if the creeper speed control is pulled to the back of the machine.
Illustration 2 g00366532
Components of the Service Brake (1) Planetary carrier (2) Axle (3) Ring gear (4) Plate (5) Friction disc (6) Passage (7) Piston (8) Planetary gear (9) Pin(three) (10) Spring (11) Piston seals (12) Sun gearThe service brake consists of plate (4), friction disc (5), piston (7), and pins (9). The service brakes are located in the front axle and the rear axle. The service brakes do not require any adjustment.Plate (4) and piston (7) are held stationary by the three pins (9). The three pins (9) are fastened to the differential housing and the axle housing. Piston (7) and plate (4) are able to slide on the three pins, but piston (7) and plate (4) cannot rotate.Friction disc (5) has splines on the inside diameter that fits onto the splines of sun gear (11). Friction disc (5) rotates at the same speed as sun gear (11). Oil flows in the grooves that are on friction disc (5) in order to cool the service brakes. The cooling oil flows between friction disc (5) and plate (4) and between friction disc (5) and piston (7). The cooling oil flows in the grooves, while the brakes are applied.Planetary carrier (1) is fastened with splines to axle (2). Planetary carrier (1) rotates at the same speed as the axle. The three planetary gears (8) rotate between sun gear (12) and stationary ring gear (3) .When one or both of the brake pedals is pushed, the brake oil from the master cylinder flows through passage (6) into the differential housing. The force of the oil behind piston (7) moves piston (7) against plate (4). This causes friction between disc (5), piston (7), and plate (4). The friction causes the rotation of sun gear (12), planetary carrier (1), axle (2), and the wheel to decrease. The heat that is created is dissipated by the oil in the axle housing.When the brake pedal is released, the oil behind piston (7) is open to the reservoir and the pressure decreases. The oil pressure behind piston (7) decreases and the brake is released.Service Brake Oil Pressure Switch
Brake oil pressure switch (13) is located