6744
4
Rev. 7/16/18
PREVENTATIVE MAINTENANCE
This is the safety alert symbol used for the PREVENTATIVE MAINTENANCE section of this manual to alert you to potential personal
injury hazards. Obey all instructions to avoid possible injury or death.
IMPORTANT:
The number one cause of jack failure in air/hydraulic jacks is dirt and moisture in the air motor and/or hydraulic system.
The shop air supply should be equipped with water and dirt filter traps that should be emptied or cleaned according to a monthly
maintenance schedule. An in line oil lubricator will extend the life of air/hydraulic jacks. Inoperable jacks caused by poorly equipped
or maintained shop air systems are not eligible for warranty consideration. Contaminants can also enter the air/hydraulic system when
the shop air line is disconnected from the jack air line and the line is dropped on the floor. Contaminants in the air couplers, once
reconnected, will be driven into the system.
1. Always store the jack in a well protected area where it will not be exposed to inclement weather, corrosive vapors, abrasive dust, or any
other harmful elements. The jack must be cleaned of water, snow, sand, grit, oil, grease or other foreign matter before using.
2. The jack must be lubricated periodically in order to prevent premature wearing of parts. A general purpose grease must be applied to
the threads on the extension screw. Do not lubricate any portion of the lift saddle and make sure the saddle is free from grease, any kind
of lubricant, or debris before using the jack. Jacks found to be defective due to worn parts resulting from inadequate or no lubrication are
not eligible for warranty consideration.
3. It should not be necessary to refill or top off the reservoir with hydraulic fluid unless there is an external leak. An external leak requires
immediate repair which must be performed in a dirt-free environment by an authorized service center.
IMPORTANT:
In order to prevent seal damage and jack failure, never use alcohol, hydraulic brake fluid or transmission oil in the jack.
Use Chevron Hydraulic Oil AW ISO 32 or its equivalent Unocal Unax AW 150.
4. Every jack owner is responsible for keeping the jack labels clean and readable. Use a mild soap solution to wash external surfaces of the
jack but not any moving hydraulic components. Contact Sunex for replacement labels if not readable.
5. Inspect the jack before each use. Do not use the jack if any component is cracked, broken, bent, shows sign of damage or leaks
hydraulic fluid. Do not use the jack if it has loose or missing hardware or components, or is modified in any way. Take corrective
action before using the jack again.
6. Any hydraulic repairs within the warranty period must be performed by an authorized service center.
INSPECTION
Visual inspection should be made before each use of the jack, checking for leaking hydraulic fluid and damaged, loose or missing parts.
Each jack must be inspected by a manufacturer’s repair facility immediately if subjected to an abnormal load or shock. Any jack which
appears to be damaged in any way, is found to be badly worn, or operates abnormally MUST BE REMOVED FROM SERVICE until necessary
repairs are made by a manufacturer’s authorized repair facility. It is recommended that an annual inspection of the jack be made by a
manufacturer’s authorized repair facility and that any defective parts, decals or warning labels be replaced with manufacturer’s specified
parts. A list of authorized repair facilities is available from the manufacturer.
PROPER STORAGE
It is recommended that the jack be stored in a dry location with all wheels touching the ground on a relatively level surface.
TROUBLESHOOTING
OWNER'S MANUAL
6744
CAPACITY: 44 TON
TRUCK AXLE JACK WITH AIR RETURN
PROBLEM
ACTION
1. Unit will not lift rated load.
Purge air from hydraulic system by following procedure under
SETUP.
2. Unit will not sustain rated load or feels “spongy” under rated load. Purge air from hydraulic system as above.
3. Unit will not lift to full height.
Purge air from hydraulic system as above.
4. Handle tends to raise up while the unit is under rated load.
Pump the handle rapidly several times to push oil past ball valves in
power unit.
5. Unit still does not operate.
Contact Sunex authorized hydraulic service center.
