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.

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	g00488577
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	g00488576
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	g00488578
Removing Batteries and Battery Tray (5) Disconnect Switch. (6) Battery. (7) Bolts. (8) Battery tray.

4. Raise the engine hood. Prop the hood support. Place disconnect switch (5) in the OFF position.

5. Disconnect battery cables from the batteries (6) .

6. Remove two bolts (7) that are on the front of the battery tray (8) . Loosen the third bolt on the rear of the battery tray (8) . Rotate the front side of the battery tray (8) toward the rear of the machine in order to access the pump.

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Illustration 4	g00488573
Pressure Tap for the Signal Oil (9) Pressure tap for the signal oil is located behind the crossover relief valve.

7. Install one 6V-4143 Coupler Assembly to each end of 6V-3014 Hose . Install 6V-3989 Unvalved Nipple to 8T-0850 Hydraulic Pressure Gauge . The pressure gauge has a range of 0 to 4000 kPa (0 to 580 psi). Install the pressure gauge to one end of one 6V-3014 Hose . Install the other end of the hose to the pressure tap for the signal oil (9) .

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Illustration 5	g00488574
The location of the pressure tap for the high pressure oil of the drive loop. The pressure tap is located under the hydrostatic pump. (10) Pressure tap for the high pressure oil of the drive loop.

8. Install one 6V-4143 Coupler Assembly to each end of 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) to one end of the 6V-3014 Hose . Install the other end of the hose to the pressure tap for the high pressure oil of the drive loop (10) .

9. Rotate the battery tray (8) into the proper position. Tighten three bolts (7) on the battery tray. Ensure that the test hoses are not pinched. Connect the battery cables. Place the disconnect switch in the ON position.

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Illustration 6	g00488575
Location of Pressure Tap on Front Axle Housing (11) Pressure tap for the service brake.

10. Install one 6V-4143 Coupler Assembly to each end of 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 (11) that is on the axle assembly.

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

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

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

14. With the machine at low idle, raise the empty bucket or attachment slightly.

15. Move the directional control lever to the FORWARD direction. The parking brake is still ENGAGED. If the machine is equipped with a speed select switch, press the speed select switch to SLOW. If the machine is equipped with a creeper speed control, move the lever for the creeper speed control all the way forward into the SLOW detent.

16. Increase the engine speed until the high pressure oil of the drive loop is 15000 ± 5000 kPa (2175 ± 725 psi) .

17. Slowly apply the service brake until the high pressure oil of the drive loop decreases to 6000 ± 2000 kPa (870 ± 290 psi) .

18. Record the signal oil pressure.

19. Continue to apply the service brake until the service brake pressure is 500 ± 200 kPa (75 ± 30 psi) .

20. Record the second signal oil pressure.

21. The first signal oil pressure should be larger than the second signal oil pressure. This verifies that the signal oil pressure during the inching mode is greater than the signal oil pressure during braking.

22. If the signal oil pressure during the inching mode is lower than the signal oil pressure during braking, then check the adjustment for the inching valve. Refer to Systems Operation and Testing and Adjusting, SENR6772-01, "Service Brake Control - Adjustment" .

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

24. Remove all of the test equipment.