24
Presto Lifts
PDL Manual
7.
Troubleshooting
PROBLEM
POSSIBLE CAUSE
CHECK
Lift will not raise
Load too heavy
Make sure the load does not exceed the rated
capacity.
Power unit not receiving
power.
Verify that the power unit is receiving power.
See
Section 8. Electrical.
Hand controls may be
malfunctioning or may not be
receiving power.
Verify that the controls are receiving power
and are functioning correctly.
See Section
Motor contactor may be
malfunctioning.
Verify motor contactor is functioning.
See
Section 8. Electrical.
Motor may be turning in wrong
direction.
Swap any two phases of the motor power leads.
Hydraulic Fluid low
With lift in fully lowered position the fluid level
should be approximately 3/4” from the top of the
tank.
Lift has reached it upper limit. Upper limit switch may need to be adjusted
Motor voltage too low
Supply voltage must be ± 10% of the rated
voltage at the motor terminals.
Tank breather plugged
Make sure breather plug on hydraulic tank is
installed and not blocked.
Suction filter is clogged
Clean suction filter.
Vacuum leak in the suction
line
Check all fittings and hoses for damage or loose
connections.
Down valve may be energized Check for correct voltage to down valve and
solenoid valve.
Missing coupling between
motor and pump (if
applicable).
Check to make sure the coupling between the
pump and motor has been installed.
(Machines
manufactured before September 2012).
Pressure relief valve is
activated.
If there is a loud squealing noise the pressure
relief valve may be activated. – Contact
Customer Service for assistance.
External Hydraulic leak
Inspect all hoses, connections, and cylinders for
leaks.
Lift fails to hold
(Drifts down)
Down valve may be leaking
internally.
Remove the down valve and inspect for debris
which may be preventing it from closing.
C
ontact Customer Service for procedure.
Down valve may be energized Check the solenoid with a volt meter.
Cylinder may be leaking
Check for fluid leaks.