NUT-SPECIAL 3144019 - Caterpillar

Illustration 1 g03531741
Service Brake Pedal
Depress the inching pedal past the half way point to start to engage the service brakes. The service brakes will give a full command when the inching pedal is fully pressed. 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 turned down all the way (anti-clockwise).
Illustration 2 g03539057
Components of the Service Brake
(1) Differential Housing
(2) Axle
(3) Friction Disc (X 4 /side)
( 4) Plate (X 3 / side)
( 5) Drive Shaft (Differential to Final Reduction)
( 6) Oil passage
(7) Piston
(8) Piston Seals
(9) Automatic Stroke Regulation Spring
(10) Return SpringThe service brake consists of three plates (4), four friction discs per axle side (3), and piston (7). The service brakes are located in the front axle and the rear axle. The service brakes do not require any adjustment as this function is controlled by automatic regulation spring (9). The three plates (4) are held stationary by lugs in the axle housing (2). The piston (7) is held stationary by the pilot bolts in the automation regulation springs (9). The piston (7) and plates (4) are able to slide but piston (7) and plates (4) cannot rotate. Friction disc (5) has splines on the inside diameter that fits onto the splines of axle shaft (5). Friction disc (3) rotates at the same speed as axle shaft (5). Oil flows in the grooves that are on friction disc (3) to cool the service brakes. The cooling oil flows between friction discs (3) and plates (4) and between friction disc (5) and piston (7). The cooling oil flows in the grooves, while the brakes are applied. When one or both (if equipped) of the brake pedals is pushed, the brake oil from the master cylinder flows through passage (6) into the axle housing. The force of the oil behind piston (7) moves piston (7) against plate (4) and differential housing (1). This causes friction between the discs (5), piston (7), plates (4) and differential housing (1). The friction causes the rotation of axle shaft (5), 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 by return springs (10).Brake Accumulator Pressure Sensor
Illustration 3 g03531819Brake accumulator pressure sensor (11) is on the left side of the machine under the operator platform. The sensor is attached to the brake charging valve.
Illustration 4 g06090646
Location of the Light for the Service Brake Oil Pressure Switch
(12) Light for the service brake oil pressure switch.
Brake oil pressure indicator (12) is on the center monitor in the operator cab. When the oil pressure in the accumulator charging valve drops below the minimum operating pressure, brake oil pressure indicator (12) turns on.