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| Illustration 1 | g00685337 |
Brake System Schematic (1) Parking brake valve (rear). (2) Parking brake valve (front). (3) Travel motor (front). (4) Parking brake. (5) Travel motor (rear). (6) Parking brake. (7) Accelerator pedal. (8) IQAN monitoring and control system. (9) Secondary brake pedal. (A) Pressure line from the charge pump. | |
The parking brakes are released with hydraulic oil pressure. The parking brakes are engaged mechanically with spring force.
When accelerator pedal (7) is released, parking brake valve (1) and (2) shifts downward. This allows oil to return to the hydraulic tank and the spring in the travel motor engages the brakes.
Generally, destroking of the power train pumps is sufficient braking force. The IQAN controls the response time for the pumps to destroke when you release the accelerator pedal. If the machine travels at full speed and you release the accelerator pedal completely, the machine will slow down smoothly. However, the machine is equipped with a secondary brake.
When accelerator pedal (7) is released or secondary brake pedal (9) is engaged, an electrical signal is sent to IQAN (8). IQAN (8) then cuts off the electrical signal to the solenoids of parking brake valve (1) and (2) .
The lack of an electrical signal causes the spring in parking brake valve (1) and (2) to shift downward. Now, charge pump oil is blocked from flowing to the brakes in the travel motors and the charge pump oil returns to the hydraulic tank. As a result, the spring in the travel motors is overcome by the oil pressure and the brakes are engaged.
Parking Brake Valve
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| Illustration 2 | g00569829 |
Location of the Parking Brake Valves (1) Parking brake valve (rear). (2) Parking brake valve (front). (10) Hydraulic oil tank. | |
Parking brake valves (1) and (2) are mounted on the right side of the machine in front of hydraulic oil tank (10). Parking brake valve (1) and parking brake valve (2) are controlled by electrical signals that are sent from the IQAN.
Parking brake valve (2) controls the brakes on the front travel motor. Parking brake valve (1) controls the brakes on the rear travel motor.
When the brake valve is activated, charge pump oil is allowed to flow to the brake cylinders. The charge pump oil causes the brakes to release.
When the parking brake valve is deactivated, charge pump oil is blocked and oil from the brake is allowed to return to the hydraulic oil tank. As the oil is returning to the tank, the spring overcomes the hydraulic oil pressure. This causes the brakes to be applied.
Service Brake (if equipped)
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| Illustration 3 | g00687187 |
Your machine may be equipped with a service brake pedal. Use the service brake when you are roading the machine.
The service brake pedal is located on the left side of the accelerator pedal in the cab.
On machines that are equipped with the service brake, the secondary brake is located on the right side of the accelerator pedal.
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| Illustration 4 | g00661297 |
Service Brake System Schematic ( 550 and 570 Wheel Harvester). (11) Service brake control valve. (12) Speed control valve. (13) Differential lock control valve. (14) Travel motor (front). (15) Parking brake. (16) Travel motor (rear). (17) Parking brake. (18) Service brake valve. (19) Parking brake valve (rear). (20) Parking brake valve (front). (B) Pressure line from the charge pump. | |
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| Illustration 5 | g00685477 |
Service Brake System Schematic ( 580 Wheel Harvester). (11) Service brake control valve. (12) Speed control valve. (13) Differential lock control valve. (14) Travel motor (front). (15) Parking brake. (16) Travel motor (rear). (17) Parking brake. (18) Service brake valve. (19) Parking brake valve (rear). (20) Parking brake valve (front). (B) Pressure line from the charge pump. (C) Supply to the parking brake valve. | |