Parts List & Operating Instructions Form No. 107191, Back of Sheet 2 of 2
Preventive Maintenance
IMPORTANT: The greatest single cause of failure in hydraulic units is dirt. Keep the service jack clean and well
lubricated to prevent foreign matter from entering the system. If the jack has been exposed to rain, snow, sand, or grit, it
must be cleaned before it is used.
1. Store the jack in a well-protected area where it will not be exposed to corrosive vapors, abrasive dust, or any other
harmful elements.
2. Regularly lubricate the moving parts in the wheels, arm, and handle.
3. Replace the oil in the reservoir at least once per year. To check the oil level, lower the lift arm completely. Remove the
rubber filler plug. Oil level should be at the bottom of the filler plug hole. If necessary, add automatic transmission fluid,
and install the filler plug. IMPORTANT: The use of alcohol, hydraulic brake fluid could damage the seals and result
in jack failure.
4. Inspect the jack before each use. Take corrective action if any of the following problems are found:
a. cracked, damaged housing c. leaking hydraulic fluid e. loose hardware
b. excessive wear, bending, other damage d. scored, damaged piston rod f. modified equipment
5. Keep warning labels and instructional decals clean and readable. Use a mild soap solution to wash external surfaces
of the jack.
Troubleshooting Guide
Repair procedures must be performed in a dirt-free environment by qualified personnel who are familiar with this
equipment. CAUTION: Inspection, maintenance, and repair procedures must be performed when the jack is free
of a load (not in use).
Trouble Cause Solution
Jack does not lift
Jack lifts only partially
Jack advances slowly
Jack lifts load, but doesn’t hold
Jack leaks oil
Jack will not retract
Jack retracts slowly
1. Release valve is open.
2. Low/no oil in reservoir.
3. Air-locked system.
4. Load is above capacity of jack.
5. Delivery valve and/or bypass valve not
working correctly.
6. Packing worn out or defective.
1. Close release valve.
2. Fill with automatic transmission fluid and
bleed system.
3. Bleed system.
4. Use correct equipment.
5. Clean to remove dirt or foreign matter.
Replace oil.
6. Replace packing.
1. Too much or not enough oil.
1. Check oil level.
1. Pump not working correctly.
2. Leaking seals.
1. Rework pump.
2. Replace seals. (Seal kit No. 501816 is
available from OTC.)
1. Cylinder packing is leaking.
2. Valve not working correctly (suction,
delivery, release, or bypass).
3. Air-locked system.
1. Replace packing.
2. Inspect valves. Clean and repair seat
surfaces.
3. Bleed system.
1. Worn or damaged seals.
1. Replace seals.
1. Release valve is closed.
1. Open release valve all the way
counterclockwise (CCW). May be
necessary to clean release valve.
1. Cylinder damaged internally.
2. Return spring is damaged.
3. Link section is binding.
1. Send jack to OTC-authorized service
center. (Refer to OTC Form No. 104031.)
2. Replace return spring.
3. Lubricate or replace link section.
