When a ISUZU garbage truck's hydraulic system malfunctions, first confirm that the power take-off (PTO) is properly engaged, the hydraulic oil level in the tank is sufficient, and the suction pipe ball valve is fully open. If the hydraulic mechanism still does not respond, proceed with the following system checks.
First, ensure there is sufficient hydraulic oil in the tank, refilling if necessary. Next, inspect the oil supply line from the tank to the oil pump for signs of deterioration or collapse. If damage is found, replace the intake pipe.
Next, inspect the gear pump for malfunctions. Install a pressure gauge and adjust the pressure regulating screw to determine if the system reaches the specified pressure. If the desired pressure is not reached even after fully tightening the adjusting screw, the gear pump may be defective and must be replaced.
If the gear pump is functioning properly, the problem may be caused by a clogged spool in the multi-way reversing valve. In this case, remove the valve plug, clean out any debris, and reinstall it to restore normal operation.
