RM-250C Reclaimer Mixer Machine Systems Caterpillar

Checks For Leakage In Air Circuit

Note: It is possible to hear the sound of air leakage. Air leakage can be seen when water with soap (soapy water) is put on the connections, valves and hoses.

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Illustration 1	g00765765
Air Tank (View from right side of the engine) (1) Drain valve for the air reservoir

1. Remove valve (1) and install 0 to 1380 kPa (0 to 200 psi) gauge in the air reservoir.

2. Start the engine and allow the air pressure to increase to the cut-out pressure. Stop the engine. NOTE: The governor cut-out pressure is set at 825 ± 35 kPa (120 ± 5 psi). If the cut-out pressure is not correct, see the subject Air Compressor Governor.

3. Hold the brake pedal in the down position.

4. Apply soapy water to all connections and valves in the air circuit. Check for leakage (bubbles). NOTE: If the air pressure in the reservoir decreases to the cut-out pressure of approximately 825 ± 35 kPa (120 ± 5 psi), start and run the engine until the air pressure reaches the cut-out pressure.

5. Release the brake pedal.

6. Apply soapy water on the exhaust diaphragm of each brake control valve. Check for leakage (bubbles).

7. Correct any leakage that is found by tightening or installing new fittings, seals or hoses.

8. Remove the gauge and install drain valve (1) .

   Note: When you check the valves for leakage, be sure to check the exhaust passages for restrictions. A restriction in an exhaust passage will restrict the release of pressure air during normal operation.

Air Compressor Governor

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Illustration 2	g00765765
Air Tank (View from right side of the engine) (1) Drain valve for the air reservoir

1. Remove valve (1) and install 0 to 1380 kPa (0 to 200 psi) gauge in the air reservoir.

2. Start the engine and allow the air pressure to increase to the cut-out pressure.

3. Read the cut-out pressure on the gauge.

4. Rapidly push the brake pedal down several times.

5. Read the cut-in pressure on the gauge.

6. The correct cut-out pressure is 825 ± 35 kPa (120 ± 5 psi). The correct cut-in pressure is 665 kPa (95 psi). If the pressures are not correct, adjust the air compressor governor.

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Illustration 3	g00765766
Air Compressor And Governor (2) Locknut (3) Adjustment screw (4) Cover

Note: Adjustment screw (3) and locknut (2) are under cover (4) .

7. Use this procedure to adjust the governor.

   1. Remove cover (4) from the governor.

   2. Loosen locknut (2) on adjustment screw (3) .

   3. Turn adjustment screw (3) counterclockwise in order to increase the cut-out pressure or turn the adjustment screw clockwise in order to lower the cut-out pressure. One turn of adjustment screw (3) changes the pressure approximately 140 ± 35 kPa (20 ± 5 psi). The cut-in pressure will change the same amount.

8. If adjustment screw (3) does not change the cut-out pressure, the unloading valves in the air compressor are not working correctly.

9. If the difference between the cut-in pressure and the cut-out pressure is not correct, the governor is not working correctly.

10. Remove the gauge and install drain valve (1) .

Test for Recovery of Air System

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Illustration 4	g00765767
Control Console (1) Air system pressure gauge

1. Start and run the engine at high idle.

2. Allow air pressure to build up to 690 ± 69 kPa (100 ± 10 psi) on air system pressure gauge (1) .

3. Pump the brake pedal ten times in rapid succession.

4. Record the time that is required for the air system to recover to 690 ± 69 kPa (100 ± 10 psi) on air system pressure gauge (1). Maximum allowable time for recovery is twenty seconds.

Adjustments for the Air Chamber And the Brake Shoe

Illustration 5	g00765769
Air Chamber And Brakes (1) Brake drum (2) Brake shoe (3) Brake actuator (4) Brake chamber (5) Lock bolt (6) Two adjusters for the brake shoe

Adjustment for the Installation of the Air Chamber

1. When the wedge assembly is in place and the nylon plug and the lock bolt (5) are backed out, screw air chamber (4) into brake actuator (3) until the air chamber bottoms in the actuator housing.

2. Back out the air chamber until the air hose connections are lined up.

3. Tighten lock bolt (5) to standard torque.

Adjustment for the Brake Shoe

1. With the parking brake OFF, use a feeler gauge to check clearance (A) between the center of brake shoe (2) and brake drum (1) .

2. Clearance (A) should be 0.5 to 1.0 mm (0.020 to 0.040 inch).

3. If the clearance is not correct make an adjustment at adjusters (6) .