Removal and Installation of Engine Sensors

[4] Counter balance valve troubleshooting

Problem

The motor does not rotate or motor rotation is slow.

The motor does not stop or stopping is slow.

When an external load acts on the motor and pumping operation is done, rotation variation occurs. Possible cause

pressurized oil is not reaching the motor inlet and the plunger is not switching.

Pressure is reaching the motor inlet, but foreign matter is clogging the orifice in the pilot oil path and the plunger is not switching.

There is foreign matter caught in the plunger and it is not switching.

There is foreign matter caught in the plunger, so the plunger will not return and brake force has decreased.

There is damage to the plunger spring, so the plunger will not return and brake force has decreased. Countermeasure and solution

After investigating whether pressurized oil is reaching the motor inlet side, investigate the causes of problems and countermeasures for each piece of equipment and perform inspection and repair. Measure the pressure of the return side inside the motor circuit, and check that the pressure has increased. After this, perform disassembly and remove foreign matter. Next, perform reassembly. Perform disassembly and remove foreign matter. Investigate the degree of damage according to Maintenance Procedures and reassemble the plunger if reusing is possible. If scratching make the plunger unusable, replace it using the base plate kit. Perform disassembly and remove foreign matter. Investigate the degree of damage according to Maintenance Procedures and reassemble the plunger if reusing is possible. If it is unusable, replace it using the base plate kit. Perform disassembly and replace the spring after removing foreign matter.

Foreign matter is clogging the orifice in the pilot oil path, and the plunger will not return or return is slow. Perform disassembly and remove foreign matter. Next, perform reassembly.

The plunger spring is not fit in place. Fit the spring correctly in place. The check valve is not fit in place. Fit the check valve correctly in place. The check valve spring is damaged. Perform disassembly and replace the spring after removing foreign matter. The check valve spring is not fit in place. Fit the spring correctly in place. There is foreign matter caught in the plunger and plunger movement is not smooth. Perform disassembly and remove foreign matter. After this, clean the plunger and perform reassembly.

The diameter of the pilot oil path orifice is wrong. Attach the correct orifice.

The pilot oil path orifice is not fit in place. Attach the orifice in the correct position.