2008/06/16 Caterpillar

Load Haul Dump:

R2900G (S/N: GLK1-UP; JLK1-UP)

Service Magazine SEPD0945, 16 May 2008, "Correction to Operation and Maintenance Manual, Braking System - Test ". Disregard this article. Refer to the following article.Operation and Maintenance Manual, SEBU7330, "R2900G Load Haul Dump", "Braking System - Test". This manual is part of Service Manual, RENR6948 Volume II.Operation and Maintenance Manual, SEBU7333, "R2900G Load Haul Dump", "Braking System - Test". This manual is part of Service Manual, RENR8526 Volume II.

The information for testing the parking brake holding ability has been updated.

Braking System - Test

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Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

Be sure the area around the machine is clear of personnel and obstructions. Be sure the steering frame lock is in the stored position.

Test the brakes on a dry, level surface. Fasten the seat belt before testing the brakes.

The following tests are to determine if the parking brake and the service brakes are functional. These tests are not intended to measure maximum holding effort. Brake holding effort required to hold a machine at a specific engine rpm will vary from machine to machine due to differences in engine setting, power train efficiency, etc., as well as differences in brake holding ability.

Engine rpm at beginning of machine movement, with the brake applied, should be compared against the engine rpm your specific machine was able to hold on a prior test, as an indication of system deterioration.

To carry out the brake test, first start the engine and let the brake oil pressure build up to the operating range. The parking brake will stay engaged until operating oil pressure has been reached and the parking brake control is moved to the OFF position (parking brake disengaged). Once operating oil pressure has been reached a test of the braking system can be commenced.

Service Brake Holding Ability Test

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Personal injury can result if the machine moves while testing. If the machine begins to move during test, reduce the engine speed immediately and engage the parking brake.

1. Move the transmission direction control to the NEUTRAL position. Start the engine. Raise the bucket slightly.

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Illustration 1	g00950054

2. Depress the service brake pedal.

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Illustration 2	g00947100

3. Disengage the parking brake by moving the parking brake control to the OFF position.

4. Move the transmission direction control to the SECOND SPEED FORWARD position.

5. Gradually increase engine speed to high idle. The machine should not move.

6. Reduce the engine speed to low idle. Move the transmission direction control to the NEUTRAL position. Engage the parking brake and lower the bucket to the ground. Stop the engine.

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NOTICE
If the machine moved while testing the brakes, contact your Caterpillar dealer. Have the dealer inspect and, if necessary, repair the service brake before returning the machine to operation.

Parking Brake Holding Ability Test

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NOTICE
The standard parking brake control is a pull-to-engage type. When the knob is pulled OUT, the parking brake will be engaged. Certain mining regulations require machines to be equipped with a push-to-engage parking brake control. When the knob is pushed IN, the parking brake is engaged. Before operating the machine, ensure you are familiar with the operation of the parking brake control.

Standard Pull-to-Engage Type

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Personal injury can result if the machine moves while testing the parking brake. If the machine begins to move during the test, reduce the engine speed immediately and apply the service brakes.

1. Move the transmission direction control to the NEUTRAL position. Start the engine. Raise the bucket slightly.

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Illustration 3	g00947100

2. Engage the parking brake by pulling the parking brake control knob out to the ON position.

3. Move the transmission direction control to the SECOND SPEED FORWARD position.

4. In a rapid motion, move the transmission direction control to the NEUTRAL position and then back to SECOND SPEED FORWARD position.

   Note: The parking brake indicator and the action lamp should illuminate. The action alarm should sound.

5. Gradually increase engine speed to high idle. The machine should not move.

6. Reduce the engine speed to low idle. Move the transmission direction control to the NEUTRAL position. Lower the bucket to the ground. Stop the engine.

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NOTICE
If the machine moved while testing the brakes, contact your Caterpillar dealer. Have the dealer inspect and, if necessary, repair the parking brakes before returning the machine to operation.

Optional Push-to-Engage Type

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Personal injury can result if the machine moves while testing the parking brake. If the machine begins to move during the test, reduce the engine speed immediately and apply the service brakes.

1. Move the transmission direction control to the NEUTRAL position. Start the engine. Raise the bucket slightly.

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Illustration 4	g00947103

2. Engage the parking brake by pushing the parking brake control in to the ON position.

3. Move the transmission direction control to the SECOND SPEED FORWARD position.

4. In a rapid motion, move the transmission direction control to the NEUTRAL position and then back to SECOND SPEED FORWARD position.

   Note: The parking brake indicator and the action lamp should illuminate. The action alarm should sound.

5. Gradually increase engine speed to high idle. The machine should not move.

6. Reduce the engine speed to low idle. Move the transmission direction control to the NEUTRAL position. Lower the bucket to the ground. Stop the engine.

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NOTICE
If the machine moved while testing the brakes, contact your Caterpillar dealer. Have the dealer inspect and, if necessary, repair the parking brakes before returning the machine to operation.