Troubleshooting Guide - Metal Works CAT 755 Manual

WARNING! Dangerous dynamic shock loads are created by quick opening and
closing the release handle when the load is being lowered. The resulting overload
may cause hydraulic system failure which could cause property damage and/or
severe personal injury.
4. If necessary, carefully and move the jack.
5. Transfer load immediately to appropriate support device for service or repair.
6 Maintenance
1. When not in use, store the jack in a dry location with saddle in lowest position.
2. Periodically check the piston rod for signs of rust or corrosion. Clean exposed areas with a clean oiled
cloth.
Warning: Never use sandpaper or abrasive material on these surfaces!
3. A coating of light lubricating oil to pivot points, axles and hinges will help to prevent rust and assure that
castors, foot pedal and pump assemblies move freely. Periodically lubricate the pivot points, axles and
hinges with a light lubricating oil as needed.
4. With jack in its lowest position, remove the air vent screw (19) to check the hydraulic oil level. If it is not
adequate, add high quality hydraulic jack oil as necessary. Insert and tighten the air vent screw. Then
purge away air from hydraulic system as described in 4.2.
Warning: Do not use brake fluid or any other improper fluid and avoid mixing different types of oil when
adding hydraulic oil.
5. To ensure best performance and longer equipment life, replace the complete hydraulic oil at least once
a year. With jack in its lowest position, remove the air vent screw (19), lay the jack on its side and drain
the oil into a suitable container. Ensure that no dirt gets into the system. Set the jack in its level upright
position, fill with approved hydraulic jack oil. Then replace the air vent screw (19) and purge away air
from hydraulic system as described in 4.2.
Note: Dispose of hydraulic oil in accordance with local regulations.
6. When equipment efficiency drops, purge away air from hydraulic system as described in 4.2.
7. It is recommended that an annual inspection be done by qualified technicians.

7 Troubleshooting guide

Trouble
Unit fails to extend or extends
partially
Incomplete or spongy cylinder
response when foot pedal is
pumped
Unit fails to extend when foot
pedal is pumped
Cylinder doesn't retract or retract
slow when release pedal is
activated
10
®
Cause
Low fluid level
Low fluid level
Air in system
Pressure is low
Release handle malfunction
Contamination
Release handle malfunction or
cylinder is binding
Contamination
CAT755 - NLFRENES - v1.1 - 10102013
Solution
Refer to maintenance section and
fill to correct fluid level (6.4)
Fill to correct fluid level (6.4)
Refer to maintenance section and
fill to correct fluid level (4.2)
Pressure regulating again
Pump foot pedal with release
handle open
Disassemble and clean unit
Disassemble unit;replace defective
parts
Disassemble and clean unit
EN