2013/08/27 Caterpillar

Work Tool:

B20 (S/N: MAX1-UP)

Required Parts

Required Tools

Safety Section

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Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Caterpillar dealer for replacement manuals. Proper care is your responsibility.

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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 work tools have been lowered to the ground, and the 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.

Machine Preparation

1. Position the machine on level ground.

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Illustration 1	g03424790
Position of Hammer

2. Set the hammer in the horizontal position.

3. Release the hydraulic system pressure. Refer to the Disassembly and Assembly, "System Pressure-Release" for the machine.

Rework Procedure to Replace Adjustment Screw

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Illustration 2	g03424817
(C) Valve block

1. Clean the area around the valve block (C) thoroughly in order to minimize contamination.

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Illustration 3	g03424826
(C) Valve block (3) Lock nut (4) Adjustment screw

2. Use tool (A) to loosen lock nut (3) .

3. Use tool (B) to remove adjustment screw (4) .

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Illustration 4	g03425094
(1) Port plug (2) Seal kit

4. Install o-ring seal and backup ring from seal kit (2) onto port plug (1) .

5. Apply thread lock compound (3) to the threads of port plug (1) .

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Illustration 5	g03425099
(C) Valve block (1) Port plug

6. Install port plug (1) into valve block (C) of the Hammer using tool (A) .

7. Tighten port plug (1) to a torque of 150 ± 10 N·m (111 ± 7 lb ft).

Procedure to Calibrate the Machines Auxiliary Hydraulic Circuit

This procedure will adjust the pressure and flow of the medium pressure circuit.

Perform all necessary steps in order to prepare the machine and the hammer to be calibrated safely. Refer to the Operation and Maintenance Manual of the machine for the proper safety procedures.

Before the hammer can be returned to service, the auxiliary hydraulic circuit for the machine must be calibrated. Calibrating the machine ensures that the correct flow and pressure are being delivered to the hammer. Failure to calibrate the machine properly can result in higher owning and operating costs, as well as damage to the hammer or the machine.

Note: All testing must be done with the hydraulic oil of the machine at an operating temperature of 50° C (122° F).

Procedure to Adjust the Pressure of the Auxiliary Hydraulic Circuit

Verify the setting of auxiliary relief valve (5). The pressure setting for auxiliary relief valve (5) should be set to 24,000 to 25,000 kPa (3,481 to 3,626 psi).

1. With the hammer installed on the machine, close the ball valve for the return side on the machine.

2. Install a pressure gauge capable of reading pressure above 25,000 kPa (3,626 psi).

3. Activate the auxiliary hydraulic circuit and record the pressure that is shown on the pressure gauge.

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Illustration 6	g03425328
(5) 361-8824 Relief Valve As (6) Lock nut (7) Adjustment screw

4. If the pressure for relief valve (5) is above 25,000 kPa (3,626 psi), loosen lock nut (6) and turn adjustment screw (7) counterclockwise in order to reduce the opening pressure for relief valve (5). While adjustment screw (7) is being held, tighten lock nut (6) .

   Note: Always make the final pressure adjustments on the pressure rise.

5. If the pressure for relief valve (5) is below 24,000 to 25,000 kPa (3,481 to 3,626 psi), loosen lock nut (6) and turn adjustment screw (7) clockwise in order to increase the opening pressure for relief valve (5). While adjustment screw (7) is being held, tighten lock nut (6) .

   Note: Always make the final pressure adjustments on the pressure rise.

6. Repeat Steps 4 through 6 in order to verify that the pressure for relief valve (5) is set to 24,000 to 25,000 kPa (3,481 to 3,626 psi).

7. Remove the pressure gauge and open the ball valve for the return side on the machine.

8. Proceed to "Procedure to Adjust the Flow of the Auxiliary Hydraulic Circuit".

Procedure to Adjust the Flow of the Auxiliary Hydraulic Circuit

1. Release the hydraulic system pressure. Refer to the Disassembly and Assembly, "System Pressure-Release" for the machine.

2. Close both ball valves for the auxiliary hydraulic circuit.

3. Remove the lines that connect the Hammer to the ball valves for the auxiliary hydraulic circuit.

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Illustration 7	g03425345
(8) Lock nut (9) Adjustment screw (10) 1U-1100 Pressure Reducing Valve

4. Install a flow meter onto the machines auxiliary hydraulic circuit.

5. Open both ball valves for the auxiliary hydraulic circuit.

6. Operate the auxiliary circuit of the machine and record the flow when the flow meter reads 17,000 kPa (2,466 psi). The flow should be 150 L/min (40 US gpm) at 17,000 kPa (2,466 psi). Flow is adjusted by pressure reducing valve (10) .

7. If the flow is greater than 150 L/min (40 US gpm) at 17,000 kPa (2,466 psi), loosen lock nut (8) and turn adjustment screw (9) counter-clockwise to reduce the pilot pressure to the valve spool. While adjustment screw (9) is being held, tighten lock nut (8) .

   Note: Always make the final pressure adjustments on the pressure rise.

8. If the flow is less than 150 L/min (40 US gpm) at 17,000 kPa (2,466 psi), loosen lock nut (8) and turn adjustment screw (9) clockwise to increase the pilot pressure to the valve spool. While adjustment screw (9) is being held, tighten lock nut (8) .

   Note: Always make the final pressure adjustments on the pressure rise.

9. Repeat Step 4 in order to verify that the flow to the auxiliary circuit is 150 L/min (40 US gpm) at 17,000 kPa (2,466 psi).

10. Disconnect the flow meter from the machine and reinstall the hammer onto the auxiliary circuit of the machine.