Section 5. TroubleshootingToyota Model 7HBW23 Service Manual

Symptom Tables: Lift/Lower System

No Lift or Slow Lift, Lift Motor Does Run

Possible Cause Action

Battery problemsReplace battery with fully-charged good battery.

Mechanical binding in lift mechanismRepair lift mechanism.

Low hydraulic pressure or relief valve setting Check hydraulic pressure setting and adjust if necessary. See “Adjusting Hydraulic Pump Pressure Relief Valve” on page6-53.

Relief valve contaminated or bad. (Unable to get the correct hydraulic pressure)

With Master Control ON/OFF switch OFF and battery disconnected, remove the pressure relief valve. Check for damage or contamination. Replace valve or flush system and replace the hydraulic fluid. See “Hydraulic Fluid” on page6-52.

Bad lift pump motor or brushesCheck the lift pump motor brushes. If OK, replace the pump.

Contamination found in the pumpFlush the system and replace hydraulic fluid.

Bad pumpIf lift motor is OK, remove motor from pump and rotate pump by hand. Replace pump if not OK.

No Lower, Lift and Travel OK

Possible Cause Action

Bad lower solenoid valve...With the Master Control ON/OFF switch ON, cycle the lower switch. Does the lower solenoid valve energize (click)? If YES, disconnect the battery, then slowly loosen, but DO NOT REMOVE the hydraulic line at the hydraulic pump assembly. Permit the forks to slowly lower. Have rags and drain pan ready to catch fluid.

... if the forks do not lower, check for mechanical binding in lift cylinder or fork mechanism...

...if the forks lower, remove and inspect the solenoid valve...

Replace lift cylinder or repair lift mechanism.

Inspect for free movement and for signs of contamination. Clean the solenoid valve or flush the system, clean the filter and replace hydraulic fluid.

If no contamination is found, repair or replace the solenoid valve or pump assembly.