550, 570 and 580 Wheel Harvesters Caterpillar

Releasing the Swing Motor Brakes

Hydraulic swing motors are used in order to rotate the cab and the boom. The right swing motor has a brake system. The left swing motor does not have a brake system. The brake that is in the swing motor must be released in order to rotate the cab.

The brakes in the swing motors are spring applied and released by hydraulic oil pressure. If the engine of the machine is disabled, hydraulic pressure cannot be obtained.

Illustration 1	g00868347

The disc spring (4) maintains pressure on the piston (2). The piston presses onto the brake pack (3). This stops the cab and the boom from rotating.

Hydraulic oil flows through port (1). The oil pressure presses outward onto the piston (2). The oil pressure pushes the piston against the disc spring (4) and away from the brake pack (3). This relieves pressure on the brake. The cab and the boom can now rotate.

The brake on the swing motor can be released by using a forcing bolt. Use the following procedures only if hydraulic oil pressure for the swing motors is lost.

Releasing The Brake By Using A Bolt

1. Tilt the cab. The cab must be tilted in order to access the swing motor.

2. Remove the cap (6) .

3. Install a 30 mm M16 bolt through the hole in the cover (5). Tighten the bolt into the tapped hole (7) of the piston (2) .

4. When the bolt is turned, the threads of the bolt will engage the tapped hole (7) in the piston (2). This will pull the piston away from the brake pack. Tighten the bolt until the brake is released.

5. Remove the bolt before operation of the machine.

Removing the Hose Assemblies from the Implement Control Valve

The hose assemblies that are between the implement control valve and the swing motors must also be removed. This is necessary in order for the cab to pivot after the brake is released.

1. Tilt the cab in order to gain better access to the implement control valve. The implement control valve is located at the rear of the swing plate.

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Illustration 2	g00868359
Top view of the implement control valve

2. The lines for the swing motors are located on the second spool valve from the left of the main control valve. Disconnect these two lines. Place these two lines into a suitable container.