8.Anti-Theft Protection Setting

[4]Troubleshooting for counter balance valve

Trouble Description

Motor does not rotate. Or, the rotation is slow.

Motor does not stop. Or, it takes a long time to stop.

External load works on the motor and rotation fluctuation arises when a pumping action is performed. Possible Cause Countermeasure and Solution

Pressurized oil has not reached to the intake of the motor and the plunger does not switch.

Pressure has reached to the intake of the motor but a clogged orifice of the pilot oil path prevents the plunger from switching. Check whether pressurized oil has reached to the intake side of the motor and then inspect and repair the motor by identifying the causes of problems and countermeasures for it for each piece of equipment.

Measure the pressure on the return side of the motor circuit to make sure that the pressure has risen. Disassemble the unit to remove the foreign matter. Then re-assemble the unit.

Foreign matter gotten into the plunger prevents it from switching.

Foreign matter gotten into the plunger prevents it from recovering and the brake capacity is lowered.

A broken spring of the plunger prevents it from recovering and the brake capacity is lowered.

A clogged orifice of the pilot oil path prevents the plunger from recovering or makes it take longer time to recover. Disassemble the unit to remove the foreign matter. Check the degree of the damage by following the maintenance procedures. If it is still usable, re-assemble it. If there is a serious damage, replace it by using the base plate kit.

Disassemble the unit to remove the foreign matter. Check the degree of the damage by following the maintenance procedures. If it is still usable, reassemble it. If it is no longer usable, replace it by using the base plate kit.

Disassemble the unit to remove the foreign matter and then replace the spring.

Disassemble the unit to remove the foreign matter. Then re-assemble the unit.

No spring is set in the plunger. Assemble a spring appropriately.

No check valve is set in the plunger. Assemble a check valve appropriately. The spring of the check valve is damaged. Disassemble the unit to remove the foreign matter and then replace the spring.

No spring is set in the check valve. Assemble a spring appropriately.

Foreign matter gotten into the plunger prevents it from moving smoothly. Disassemble the unit to remove the foreign matter. Clean and re-assemble the unit.

The orifice bore of the pilot oil path is wrong. Assemble an appropriate orifice in the pilot oil path.

No orifice is set in the pilot oil path. Assemble an orifice in place.