PP120 and PH126 Power Pack and Hammer Caterpillar

Work Tool Troubleshooting

Usage:

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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. 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 power pack is functioning properly.

Power Pack

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Table 1
Symptom	Possible Cause	Action
The engine turns over but the engine does not start.	No fuel	Add fuel.
	The fuel line is blocked.	Clear the blockage in the fuel line.
	The ignition switch is in the OFF position.	Turn the switch to the "ON" position.
	The engine oil is low.	Add engine oil.
	The hydraulic oil is low.	Add hydraulic oil.
	The fuel valve is in the "0" position.	Turn the fuel valve in the "1" position.
	The choke is not functioning.	Check the choke.
	The engine has malfunctioned.	Refer to the engine's manual.
The engine does not turn over or the engine is difficult to turn over.	The bypass valve is in the "ON" position.	Turn the valve to the "OFF" position.
	The engine has malfunctioned.	Refer to the engine's manual.
Hydraulic oil level is low.	Hoses are damaged.	Replace damaged hoses.
	Connections are leaking.	Check the connections for tightness and leaks.
	Hose couplings are damaged.	Replace the couplings.
	New hoses were installed. Hoses contain a significant amount of hydraulic oil that is used in the hydraulic circuit.	Replace the lost hydraulic oil.
Performance of the tool is poor.	The pressure relief setting is too low.	Adjust the pressure control valve.
	There is high back pressure.	Check the hydraulic hoses for defects or blockage.
	The hydraulic pump is worn.	Replace the pump.
	The "POD" setting is incorrect.	Adjust the "POD" setting in order to increase the engine speed.
	The bypass valve is not fully open.	Check the position of the bypass valve.
The hydraulic oil is milky in appearance.	There is air or water in the oil.	Check the connections at the hydraulic pump.
The hydraulic oil is milky in appearance.	There is air or water in the oil.	Make sure that the filler cap on the hydraulic tank is not loose.
The power pack overheats.	The power pack is placed in a location with poor air circulation.	Move the power pack in order to improve air circulation.
	The oil cooler is blocked.	Clean the oil cooler with compressed air or water. Do not use a wire brush.
	The fan is damaged.	Replace the fan.
	The back pressure is too high.	Check for obstructions in the hydraulic system.
The power pack stops suddenly.	The power pack is out of fuel.	Add fuel.
	Low hydraulic oil trips the float switch.	Add hydraulic oil.
	The engine's oil level is too low.	Add engine oil.

Hammer

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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.

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Table 2
Problem List	Probable Causes
The hammer has a slow impact rate.	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 power pack. Check the relief valve operation in the power pack. 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 power pack. Check the installation. Verify that you have correct oil flow at the recommended operating pressure of the hammer.
	The control valve is not operating properly. Check the control valve.
	The nitrogen charge has been lost in the accumulator. If the nitrogen charge has been lost, disassemble the accumulator. Check the diaphragm. Charge the accumulator. Refer to the Testing and Adjusting section that is located in the Service Manual, RENR6996, "Hydraulic Accumulator - Test and Charge".
	Hydraulic oil viscosity is too low. Use a higher viscosity of oil.
The hammer operates in an irregular manner and the impact of the tool has full power.	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 control valve and the check valve are not operating properly. Check the control valve and the check valve.
	The accumulator charge has been lost.
The hammer operates poorly and the impact of the tool has no power.	The nitrogen charge has been lost in the accumulator. If the nitrogen charge has been lost, disassemble the accumulator. Check the diaphragm. Charge the accumulator. Refer to the Testing and Adjusting section that is located in the Service Manual, RENR6996, "Hydraulic Accumulator - Test and Charge".
	The setting of the control valve is not correct.
	The hammer is used in an incorrect method.
	The control valve is not operating properly. Check the control valve.
Oil overheats.	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 power pack. Check the installation. Check the pump and the other hydraulic components.
	The hammer has an internal oil leak. Disassemble the hammer. Locate the oil leak. Replace all the O-rings and all the seals.
	Hydraulic oil viscosity is too low. Use a higher viscosity of oil.
The hammer does not work. Pressure is not built up when the trigger is activated.	There is incorrect oil flow to the hammer. Check the flow and the pressure of the power pack.
	Hoses from port "P" and port "T" are interchanged. Check the hose routing.
	The trigger valve is out of adjustment. Adjust the trigger lever or replace damaged parts.
	There are damaged seals in the bore for the spool of the valve housing. Replace the seals.
The hammer does not work. Pressure is built up when the trigger is activated.	Back pressure is too high. Maximum back pressure should be 1000 kPa (145 psi) to 1500 kPa (217 psi).
	There is a damaged coupling on the return line. Replace the return line.
	The piston sticks. This may be caused by wear to the cylinder. Push the hammer hard against the tool. Polish the cylinder.
	The spool or the auxiliary spool sticks. Disassemble the hammer. Then polish the spool.
	Seals are damaged. Replace the seals.
The hoses pulsate.	The accumulator is not functioning. Check the charge of the accumulator. Inspect the accumulator's diaphragm for damage if the accumulator will not hold a charge.
The tool falls out of the hammer.	The latch is worn. Replace the latch and the roll pins.
The tool falls out of the hammer.	The tool is worn. Replace the tool.
The hammer does not operate in all handle positions.	Check the pressure valve that is activated by the hand control lever.
	The activation lever is bent or damaged.
	The handle is bent or damaged.