Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the brake system. |
Note: Press the horn to alert personnel in the area.
Note: Test the brakes on a dry, level surface. Make sure that the area around the machine is clear. Move the machine away from other operating machines and away from personnel.
Note: If the machine is on stands, place the steering frame lock in the LOCKED position. Clear the area around the wheels in order to allow the wheels to rotate.
Note: Engage the parking brake.
REQUIRED TOOLS     | ||
Part Number     | Description     | Quantity     |
8T-0820     | Gauge 0 to 70000 kPa     | 1     |
6V-3014     | Hose Assembly     | 1     |
6V-4143     | Coupler     | 2     |
6V-3989     | Unvalved Nipple     | 1     |
- Remove the relay panel on the right side of the machine by the door.
- Disable the neutralizer by removing the parking brake alarm relay and the parking brake relay.
Illustration 1 | g00477267 |
Location of the Parking Brake Relay and Parking Brake Alarm Relay (1) Parking brake alarm relay. (2) Parking brake relay. |
- Insert 2G-5298 Wire Assembly into the relay panel at locations F3 and D5 .
Note: This will supply the power to the directional control lever. The limit switch to the parking brake control lever will be ignored.
Illustration 2 | g00477266 |
Jumper Wire Location (3) Location F3. (4) Location D5 . |
- Remove the access panel on the lower right side of the machine under the battery compartment.
- Install one 6V-4143 Coupler Assembly to each end of a 6V-3014 Hose . Install 6V-3989 Unvalved Nipple to 8T-0820 Hydraulic Pressure Gauge . The pressure gauge has a range of 0 to 70000 kPa (0 to 10000 psi). Install the pressure gauge to one end of 6V-3014 Hose . Install the other end of the hose to the pressure tap for the high pressure oil of the drive loop (5) .
Illustration 3 | g00462826 |
Pressure Tap Location for the High Pressure Oil of the Drive Loop (5) Pressure tap for the high pressure oil of the drive loop. |
- Clearly label the hydraulic test line. Secure the hydraulic line so that the pressure gauge can be viewed during the test. Do NOT hold the pressure gauge or the hydraulic line.
- Sit in the seat and fasten the seat belt.
- Start the engine. Allow the machine to reach normal operating temperature.
- With the machine at low idle, slightly raise the empty bucket or attachment. Push down and hold either brake pedal in order to apply the service brakes.
- Recheck that the parking brake control lever is pulled completely upward.
- Release the service brakes. Gradually press down the accelerator pedal until the machine moves. For (PIN: 7ZM, 9WM), the pressure gauge should indicate 21500 ± 6000 kPa (3120 ± 870 psi). For (PIN: 8ZM, 1WN), the pressure gauge should indicate 20300 ± 6000 kPa (2940 ± 870 psi) .
- Reduce the engine speed. Lower the bucket or attachment to the ground. Stop the engine.
- After repairing or replacing the parking brake components, perform this test again.
NOTICE |
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If the machine moved while testing the parking brake, inspect the parking brake components for wear or damage. Repair or replace the worn or damaged parking brake components as required before returning the machine to service. |
- If the pressure is with the specification, disconnect the hydraulic line. Disconnect the pressure gauge. Remove the 2G-5298 Wire Assembly . Install relays (1) and (2) and install the relay panel.