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| Illustration 1 | g01430991 |
Hydraulic schematic for the braking system (1) Steering cylinder (2) Steering cylinder (3) Steering cylinder crossover relief valve (4) Steering cylinder crossover relief valve (5) STIC steering pilot valve (6) Brake release cylinder (7) Pressure tap for the brake release system (8) Front wheel brakes (9) Pressure tap for the front service brake circuit (10) Secondary steering diverter valve (11) Secondary steering pump (12) Steering control valve (13) Steering release diverter valve (14) Check valve (15) Brake release sequence valve (16) Parking brake control valve (17) Rear brake accumulator (18) Front brake accumulator (19) Steering system pressure tap (20) Spool (21) Implement and steering solenoid valve (22) Service brake pedal (23) Service brake and transmission neutralizer pedal (24) Residual brake oil pressure switch for the rear brakes (25) Shuttle valve (26) Hydraulic oil cooler (27) Line from implement lift circuit (28) Selector and pressure control valve (29) Parking brake solenoid valve (30) Service brake oil pressure switch (31) Check valve (32) Pressure tap for the parking brake (33) Secondary steering flow switch (34) Primary steering flow switch (35) Check valve (36) Dual pilot check valve (37) Automatic lubrication system connection port (38) Parking brake oil pressure switch (39) Service brake control valve (40) Residual brake oil pressure switch for the front brakes (41) Brake accumulator oil pressure switch - brake application (42) Check valve (43) Steering neutralizer valve for a left turn (44) Steering neutralizer valve for a right turn (45) Check valve (46) Pressure tap for the pilot circuit (47) Pressure tap for the rear service brake circuit (48) Rear wheel brakes (49) Breaker relief valve (50) Pilot oil pressure reducing valve (51) Portable hydraulic pump quick connect coupler (52) Pressure tap for the brake accumulator charging circuit (53) Brake accumulator oil pressure switch - alert indicator (54) Pilot and braking pump (55) Steering pump (56) Hydraulic tank (57) Hydraulic filters (58) Portable hydraulic pump quick connect coupler (59) Brake accumulator charging valve | |
Recovery Bar
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If the disabled machine is in a stope or dangerous area, the recovery machine must be operated by remote control. The brake release system must only be activated by a recovery bar securely attached to the recovery machine. The recovery bar must be securely attached to the hitch of the disabled machine prior to activating the brake release system. Failure to securely attach the recovery bar may result in the disabled machine moving. Uncontrolled movement of the disabled machine can cause serious personal injury or death. When the disabled machine has been towed to a safe place, ensure that the machine is parked on level ground and the wheels are blocked securely. Be sure that the machine can not move before performing any service work on the machine. Ensure that the disabled machine cannot move before disconnecting the recovery bar. |
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If the parking brake is engaged due to a machine fault and the machine must be towed, the brake release system can be used to release the machine brakes.
The brake release system is activated by a recovery bar compressing the piston in the brake release cylinder. The brake release cylinder is located in the machine towing hitch at the rear of the machine.
The brake release system consists of the following components: brake release cylinder (6), shuttle valve (25), brake release sequence valve (15) and check valve (14).
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| Illustration 2 | g01276675 |
(6) Brake release cylinder (typical example) | |
Brake release cylinder (6) is located on the rear of the machine.
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| Illustration 3 | g01250772 |
(15) Brake release sequence valve | |
Brake release sequence valve (15) is located on the left side of the rear frame.
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| Illustration 4 | g01431882 |
(25) Shuttle valve | |
Shuttle valve (25) is located on the left side of the rear frame.
When the brake release system is activated, the recovery bar compresses the piston rod in brake release cylinder (6) against spring pressure. The hydraulic oil in the brake release cylinder is forced from the cylinder and directed through shuttle valve (25) to the wheel brakes. The oil pressure then disengages the parking brake section of the wheel brakes.
When the recovery bar is removed, the brake release system is deactivated and the piston rod in brake release cylinder (6) is returned by spring pressure. The hydraulic oil disengaging the parking brake is now returned to brake release cylinder (6). The parking brake will now be engaged.
Brake release sequence valve (15) ensures that the brake release system is disabled when the engine is running and the parking brake is disengaged.
Recovery Hook
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If the disabled machine is in a stope or dangerous area, the recovery machine must be operated by remote control. The brake release system must only be activated by a tow line securely attached to the recovery machine. The tow line must be securely attached to the recovery hook of the disabled machine prior to activating the brake release system. Failure to securely attach the tow line may result in the disabled machine moving. Uncontrolled movement of the disabled machine can cause serious personal injury or death. When the disabled machine has been towed to a safe place, ensure that the machine is parked on level ground and the wheels are blocked securely. Be sure that the machine can not move before performing any service work on the machine. |
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If the parking brake is engaged due to a machine fault and the machine must be towed, the brake release system can be used to release the machine parking brake.
The brake release system is activated by an external force being applied to the recovery hook. The recovery hook is located at the rear of the machine.
The brake release system consists of the following components: brake release cylinder (6), shuttle valve (25), brake release sequence valve (15) and check valve (14).
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| Illustration 5 | g01250775 |
Rear view of the machine (typical example) (6) Brake release cylinder (60) Recovery hook | |
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| Illustration 6 | g01250772 |
(15) Brake release sequence valve | |
Brake release sequence valve (15) is located on the left side of the rear frame.
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| Illustration 7 | g01431882 |
(25) Shuttle valve | |
Shuttle valve (25) is located on the left side of the rear frame.
When the brake release system is activated, recovery hook (60) compresses the piston rod in brake release cylinder (6) against spring pressure. The hydraulic oil in the brake release cylinder is forced from the cylinder and directed through shuttle valve (25) to the wheel brakes. The pressure oil then disengages the parking brake section of the wheel brakes.
When the external force on recovery hook (60) is removed the brake release system is deactivated, and the piston rod in brake release cylinder (6) is returned by spring pressure. The hydraulic oil disengaging the parking brakes is now returned to brake release cylinder (6). The parking brakes will now be engaged.
Brake release sequence valve (15) ensures that the brake release system is disabled when the engine is running and the parking brake is disengaged.
Steering Release
In the event of a machine fault and the machine must be towed, the optional brake release system can be used to release the machine steering.
The steering release is activated by either of two methods: A recovery bar attached to the recovery machine or by a tow line attached to the recovery hook of the disabled machine. Both methods exert an external force on the piston in the brake release cylinder.
The steering release system consists of the following components: brake release cylinder (6), brake release sequence valve (15) and steering release diverter valve (13).
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| Illustration 8 | g01276675 |
(6) Brake release cylinder (typical example) | |
Brake release cylinder (6) is located on the rear of the machine.
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| Illustration 9 | g01250772 |
(15) Brake release sequence valve | |
Brake release sequence valve (15) is located on the left side of the rear frame.
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| Illustration 10 | g01275481 |
(13) Steering release diverter valve | |
Steering release diverter valve (13) is mounted on the steering control valve. The steering control valve is located on the rear frame behind the articulation hitch.
When the brake release system is activated, oil from brake release cylinder (6) is sent to steering release diverter valve (13). The pressure oil from brake release cylinder (6) activates steering release diverter valve (13). Steering release diverter valve (13) allows oil flow between the rod end and the head end of the steering cylinders. The machine will articulate freely whilst being towed.
Brake release sequence valve (15) ensures that the steering release system is disabled when the engine is running.