938H Wheel Loader and IT38H Integrated Toolcarrier Power Train Caterpillar

Calibration of Left Brake Pedal Position Sensor with Electronic Technician

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Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. Prevent possible injury by performing the procedure that follows before working on the machine.

1. Start the machine.

2. Park the machine on a smooth, level surface.

3. Shift the transmission direction control switch to the NEUTRAL position.

4. Lower the bucket or the work tool to the ground.

5. Engage the parking brake.

6. Place blocks in front of the wheels and behind the wheels.

7. Install the steering frame lock.

8. Allow only authorized personnel on the machine. Keep unauthorized personnel off the machine and in clear sight of the operator.

The software program that will be used for this test procedure is the Caterpillar Electronic Technician (ET). The Caterpillar Electronic Technician is a software program that can be used on an IBM-compatible personal computer.

ReferenceFor more information about the use of Electronic Technician, refer to Testing and Adjusting, "Using Caterpillar Electronic Technician (ET) to Determine Diagnostic Codes" for the machine that is being serviced.

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Illustration 1	g01432279

1. Open the software program (ET). Select the "Transmission 938G" menu item.

2. Select the "Service" menu in order to begin the calibration procedure. Then select "Calibrations". A second menu will be displayed. Select "Nuetralization Setpoint Calibration" from the second menu.

3. The next screen is the initial calibration screen. Once "Nuetralization Setpoint Calibration" has been selected, the screen displays instructions for calibration. The top display area displays status parameters that are monitored during the calibration. The middle display area displays information about the status of the calibration. The display area at the bottom will display the conditions for the setup and the bottom will also display the instructions for the calibration.

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Illustration 2	g01432280

4. The display area will show the following conditions for setup:
   • The engine must be running.

   • The parking brake must be set.

   • The shift lever must be in the neutral position.

5. Install the 1U-5482 Pressure Adapter and the 1U-5481 Pressure Gauge to the pressure tap on the rear axle.

6. Press the "Next" button in order to start the calibration.

   Note: If the conditions for the setup are not correct, the condition that is not correct will be displayed in the middle display area. Once the conditions are correct, the calibration will begin.

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Illustration 3	g01432282

7. While the calibration is running, press the left brake pedal until the brake pressure reading on the gauge is the same value as the display on the screen in the bottom area. When this pressure has been reached, continue pressing the left brake pedal and press the "Next" button.

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Illustration 4	g01432329

8. Completely release the left brake pedal and press the "Next" button in order to end the calibration.

9. If the calibration needs to be restarted, press the "Restart" button.

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Illustration 5	g01432284

10. If the calibration was completed successfully, press the "Finish" button.