H140CS and H160CS Hydraulic Hammers Hydraulic Hammer Troubleshooting Caterpillar

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Personal injury or death can result from improper troubleshooting and repair procedures. The following troubleshooting and repair procedures should only be performed by qualified personnel familiar with this equipment.

Operational Checks

Operate the work tool in single direction flow and at different engine speeds. Note the noises that are not normal and find the sources of the noises. If the work tool is not operating properly, refer to the following troubleshooting problem list.

Verify that the hydraulic system of the host machine is functioning properly. Refer to the Testing and Adjusting procedures of the host machine.

Troubleshooting Problem List

Note: This section contains the troubleshooting procedures for the hydraulic hammers.

The hammer does not start.

Probable Causes

• The piston is in the lower hydraulic brake. The top of the tool will push the piston out of the hydraulic brake area.

• The pressure control valve does not open. When you operate the pressure control valve, check that the pressure line will pulsate. This will indicate if the pressure control valve has opened. If the valve does not operate, you should check the mechanical connections, the pilot pressure, and the electronic control.

• The relief valve in the hydraulic circuit opens at low pressure. The operating pressure of the hammer has not been reached. Check the installation. Measure the high pressure on the inlet side of the hammer. Check the relief valve operation.

• Oil leakage from the pressure line to the low pressure line in the hydraulic circuit of the host machine. Check the installation. Verify that you have correct oil flow at the recommended operating pressure of the hammer.

• Back pressure is excessive in the return line. Check for possible restriction in the return line.

• The pressure control valve and the check valve are not operating properly. Check the pressure control valve and the check valve.

• The piston is not operating properly. After all other possibilities have been examined, disassemble the hammer. Inspect the piston for cracks or severe gouges. If the cracks or gouges are present, replace the piston.

• Grease is built up between the piston and the top of the tool. Remove the tool. Wipe the excessive grease off the top of the tool.

• The pressure lines and the return lines have been installed in reverse order. Correct the installation of the hoses.

• The ball valve for the pressure line and/or the ball valve for the return line is closed. The ball valves should be locked in the open position during hammer operation.

• If the hydraulic lines are equipped with quick disconnects, check that the quick disconnects are working properly and that the quick disconnects are not damaged.

The hammer has a slow impact rate.

Probable Causes

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The accumulator is filled with dry nitrogen. Sudden release of nitrogen pressure can cause personal injury. To avoid personal injury, release the nitrogen pressure from the accumulator before disassembly.

• Oil has overheated. Check for a fault in the oil cooling system. Check for an internal leak in the hammer. Check the hydraulic circuit of the host machine. Check the relief valve operation in the host machine. Verify that you have correct oil flow at the recommended operating pressure of the hammer.

• Back pressure is excessive in the return line. Check the installation. Check the size of the return line.

• The relief valve in the hydraulic circuit remains open at low pressure. Check the installation. Check the relief valve operation. Verify that the relief valve is at the proper setting. Measure the high pressure on the inlet side of the hammer.

• Oil leakage from the pressure line to low pressure in the hydraulic circuit of the host machine. Check the installation. Verify that you have correct oil flow at the recommended operating pressure of the hammer.

• The pressure control valve and the check valve are not operating properly. Check the pressure control valve and the check valve.

• The nitrogen charge has been lost in the accumulator. If the nitrogen charge has been lost, disassemble the accumulator. Check the membrane. Charge the accumulator. Refer to the Testing and Adjusting section of the Service Manual, "Hydraulic Accumulator - Test and Charge".

• Hydraulic oil viscosity is too low. Use a higher viscosity of oil.

• The oil flow from the host machine is low or incorrect.

The hammer operates in an irregular manner and the impact of the tool has full power.

Probable Causes

• The relief valve in the hydraulic circuit remains open at low pressure. The operating pressure has not been reached. Check the installation. Check the relief valve operation. Measure the high pressure on the inlet side of the hammer.

• The pressure control valve and the check valve are not operating properly. Check the pressure control valve and the check valve.

• The accumulator charge has been lost.

• There is a lack of feed force from the host machine. Refer to the Operation and Maintenance Manual, SEBU7382, "Operating Technique" that is located within Owner's Manual, RENR4426.

The hammer operates poorly and the impact of the tool has no power.

Probable Causes

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The accumulator is filled with dry nitrogen. Sudden release of nitrogen pressure can cause personal injury. To avoid personal injury, release the nitrogen pressure from the accumulator before disassembly.

• The nitrogen charge has been lost in the accumulator. If the nitrogen charge has been lost, disassemble the accumulator. Check the membrane. Charge the accumulator. Refer to the Testing and Adjusting section of the Service Manual, "Hydraulic Accumulator - Test and Charge".

• The setting of the pressure control valve is not correct. Refer to the Specifications section of the Service Manual, "Pressure Control Valve " for the correct settings.

• The hammer is used in an incorrect method. For the correct working methods, refer to the Operation and Maintenance Manual, SEBU7382, "Operating Techniques" that is located within Owner's Manual, RENR4426.

• The pressure control valve and the check valve are not operating properly. Check the pressure control valve and the check valve.

Oil overheats.

Probable Causes

• The relief valve in the hydraulic circuit remains open at low pressure. The operating pressure has not been reached. Check the installation. Check the relief valve operation. Measure the high pressure on the inlet side of the hammer.

• Oil leakage from the pressure line to the low pressure in the hydraulic circuit of the host machine. Check the installation. Check the pump and the other hydraulic components.

• Replace all of the O-rings and seals. Change the diaphragm of the accumulator. Recharge the accumulator.

• Back pressure is excessive in the return lines. Check for restrictions in the return lines by checking the size of the return lines. Check the fittings.

• The hammer has an internal oil leak. Disassemble the hammer. Locate the oil leak. Replace all the O-rings and all the seals.

• The hammer is being operated incorrectly.

• Hydraulic oil viscosity is too low. Use a higher viscosity of oil. Refer to the Operation and Maintenance Manual, SEBU7382, "Lubricant Specifications" that is located within Owner's Manual, RENR4426.

• The cooling capacity of the oil cooler of the host machine is too small. Add an extra oil cooler. Refer to the Operation and Maintenance Manual, SEBU7382, "Lubricant Specifications" that is located within Owner's Manual, RENR4426.