Autoquip FREIGHTLIFT FLH - Manual (Page 97)

97
PROBLEM POSSIBLE CAUSE AND SOLUTION
Unit operates in a “spongy”
or jerky fashion.
 The load may exceed the stated capacity of the unit.
Overloading causes the pressure switch valve to
activate and deactivate if the “UP” button is
depressed. (Motor may start and stop if this condition
exists.) Remove the excess load.
 The hydraulic system may have air in it. The unit
requires bleeding.
 Check for oil starvation.
 The rollers may be binding. Check and repair.
 The platform carriage may be binding in the guide
ways. Check and repair.
 The cylinder may be binding internally or externally.
Check and repair.
 The pressure switch may be turning the motor on
and off. Check and repair.
The Freightlift lowers too
slowly with a load.
 Check for a pinched hose or tubing.
 The “DOWN” valve may be malfunctioning. Check
and replace control valve.
 The “DOWN” valve solenoid mounting is loose,
preventing the valve from opening completely.
Check and repair.
 Oil is extremely heavy for the application, or low
temperature is causing a thickening of the oil.
 The “DOWN” valve solenoid may be weak and not
pulling in completely (it will usually “chatter”). Check
the control voltage. Check and repair or replace.
Freightlift raises, then
lowers back slowly.
 The “DOWN” solenoid valve may be energized in the
“OPEN” position. Remove the solenoid coil and
recheck. If the lift does not hold with the solenoid
coil removed, replace the down valve cartridge.
 The hydraulic cylinder rod seal may be leaking.
Check to see if there is hydraulic oil running down
the outside of the cylinder barrels at the rod end.
Repair as necessary. (NOTE: a small amount of oil
at the bottom of the rod is normal and desirable for
proper lubrication of the cylinder. A leak would
cause oil to flow from the rod area when the lift is in
the raised position.)
 Check valve in the pump or Detatrol may be
contaminated or defective. Repair or replace.
TROUBLESHOOTING ANALYSIS