IT14G Integrated Toolcarrier and 914G Wheel Loader Braking System Caterpillar

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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.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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.

1. Remove the access panel on the lower right side of the machine by the door.

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Illustration 1	g00477165
Location of the Parking Brake Relay and Parking Brake Alarm Relay (1) Parking brake alarm relay. (2) Parking brake relay.

2. Disable the neutralizer by removing the parking brake alarm relay and the parking brake relay.

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Illustration 2	g00477166
Jumper Wire Location (3) Location F3. (4) Location D5 .

3. 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.

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Illustration 3	g00434683
Master Cylinder for (PIN: 7ZM1-1178ZM1-1249WM1-871WN1-94) (5) Linkage. (6) Nut. (7) Stud. (8) Lever.

4. The master cylinder for (PIN: 7ZM1-117, 8ZM1-124, 9WM1-87, 1WN1-94) is shown in Illustration 3. The master cylinder is located under the floor panels and on the left side of the frame. Remove the nut (6) from the stud (7) . Disconnect linkage (5) , which connects the inching valve to the master cylinder for the service brakes.

   Note: Rotate the lever (8) fully forward. This will prevent the inching valve from actuating during the remainder of the test procedure.

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Illustration 4	g00464041
Master Cylinder for (PIN: 7ZM118-5998ZM125-4999WM88-12981WN95-898) (5) Linkage. (8) Lever.

5. The master cylinder for (PIN: 7ZM118-599, 8ZM125-499, 9WM88-1298, 1WN95-898) is shown in Illustration 4. The master cylinder is located under the floor panels and on the left side of the frame. Linkage (5) connects the inching valve to the master cylinder for the service brakes. Disconnect the linkage (5) from the lever (8) . The lever is attached by a ball joint with a quick release.

   Note: Rotate the lever (8) fully forward. This will prevent the inching valve from actuating during the remainder of the test procedure.

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Illustration 5	g00462282
Pressure Tap Location for the High Pressure Oil of the Drive Loop (9) Pressure tap for the high pressure oil of the drive loop.

Note: Remove the access panel below the battery.

6. 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 pressure tap for the high pressure oil of the drive loop (9) .

7. Purge the service brakes of air. Refer to Systems Operation and Testing and Adjusting, SENR6772-01, "Brake System Air- Purge" .

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Illustration 6	g00463280
Location of Pressure Tap on Front Axle Housing (10) Pressure tap for the service brake.

8. Install one 6V-4143 Coupler Assembly to each end of a 6V-3014 Hose . Install 6V-3989 Unvalved Nipple to 8T-0848 Hydraulic Pressure Gauge . The pressure gauge has a range of 0 to 16000 kPa (0 to 2320 psi). Install the pressure gauge to one end of 6V-3014 Hose . Install the other end of this hose to pressure tap for the service (10) that is on the axle assembly.

9. Clearly label the hydraulic test lines. Secure the hydraulic lines so that the pressure gauge can be viewed during the test. Do NOT hold the pressure gauge or the hydraulic line.

10. Sit in the seat and fasten the seat belt.

11. Start the engine and allow the machine to reach normal operating temperature.

12. With the machine at low idle, raise the empty bucket or attachment slightly. Push down and hold either brake pedal in order to apply the service brakes. Disengage the parking brake.

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NOTICE
Do not drive through the service brake more than 15 seconds.

13. Move the directional control lever to the FORWARD direction. If the machine is equipped with a speed select switch, press the speed select switch to FAST. If the machine is equipped with a creeper speed control, move the lever for the creeper speed control all the way forward into the FAST detent.

14. Apply the service brake until a pressure of 3500 ± 200 kPa (510 ± 30 psi) is indicated on the pressure gauge to pressure tap (10) .

15. Slowly increase the engine speed until the machine moves. Hold the service brake pedal and the accelerator pedal in that position.

16. At the same time, check the high pressure oil of the drive loop. For (PIN: 7ZM1-UP, 8ZM1-UP) standard machines, the pressure gauge should indicate 13250 ± 5000 kPa (1920 ± 725 psi). For (PIN: 1WN1-UP), the pressure gauge should indicate 25250 ± 5000 kPa (3660 ± 725 psi). For (PIN: 9WM1-UP), the pressure gauge should indicate 22500 ± 5000 kPa (3260 ± 725 psi) .

17. Move the directional control lever to the NEUTRAL position. Apply the parking brake. Stop the engine.

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NOTICE
If the high pressure oil of the drive loop is not within specification, inspect the service brake components for wear or damage. Repair or replace the worn or damaged service brake components as required and repeat this testing procedure before returning the machine to service.

18. If the pressure is not within the specification, then do the following steps in order until the pressure is within the specification.

    1. Check that the inching valve is fully closed. Repeat the test.

    2. Purge the service brakes of air. Repeat the test.

    3. Replace the master cylinder. Repeat the test.

19. If the pressure is within the specification, remove all of the test equipment. Connect linkage (1) between the inching valve and the master cylinder.

20. Remove the 2G-5298 Wire Assembly . Install relays (1) and (2) and install the relay panel.

21. Disconnect all of the test equipment.