WIRE ASSEMBLY 8D8581 - Caterpillar

Parking Brake
The location of the parking brake is in the end of the machine with the engine and transmission. The brake is on the drive shaft (2) to the front wheels of the machine. It is a mechanical brake with a brake drum (4) and two lined inner shoes.When the operator moves the brake control lever, to put on the parking brake, the cable (1) connection to the brake control moves the lever (3). The lever pushes the inner shoes against the inner surface of the brake drum (4) and keeps the drive shaft from turning.
PARKING BRAKE
1. Cable connection to brake control. 2. Drive shaft. 3. Lever. 4. Brake drum.
HYDRAULIC POWER BRAKE SCHEMATIC
1. Oil supply tank. 2. Steering control assembly. 3. Supply tank for the master cylinder. 4. Oil line from power brake to supply tank. 5. Oil line from steering control assembly to power brake. 6. Oil line from flow control valve to steering control assembly. 7. Brake calipers on front wheels. 8. Power and master cylinder for the wheel brakes. 9. Left pedal for wheel brakes. 10. Oil line from flow control valve. 11. Oil line from pump to flow control valve. 12. Oil line from relief valve to power brake. 13. Flow control valve and relief valve. 14. Right pedal for wheel brakes. 15. Neutralizer valve for transmission. 16. Pump section for loader system. 17. Pump section for steering system. 18. Oil line to loader control valves. 19. Oil line from oil supply tank to pump.
Always install the safety bar, to keep the machine straight, before doing any work under the machine. With the parking brake on, the drive shaft does not turn but the differential gears, in the drive to the front wheels, can let the wheels turn in opposite directions which will turn the machine.
The hydraulic pump oil for the steering system also operates the power brakes (when the engine is running) when either left pedal (9) or right pedal (14) is pushed for wheel brake application.The oil from the steering pump section (17) goes to flow control and relief valve (13). This valve lets only 11 U.S. gpm (41.6 lit/min) of the pump oil go to the steering control assembly (2). The hydraulic pump oil from the steering control assembly goes to the power cylinder part of the power and master cylinder (8).
OIL LINES WITH FLOOR PLATES REMOVED
5. Oil line from steering control assembly to power brake. 6. Oil line from flow control valve to steering control assembly. 8. Power and master cylinder for the wheel brakes. 10. Oil line from flow control valve to supply tank. 11. Oil line from pump to flow control valve. 12. Oil line from relief valve to power brake. 13. Flow control valve and relief valve.When a brake pedal is pushed, the pressure of the pump oil in the power cylinder increases to approximately 300 psi (21.1 kg/cm2). This pushes the power cylinder piston and the master cylinder piston. The master cylinder piston increases the pressure