12
PRESTO P4 LEVEL LOADER OWNER’S MANUAL
Troubleshooting Check List
All servicing should be done by qualified
personnel. Qualified personnel should be able
to read and understand wiring and hydraulic
diagrams. They should be able to troubleshoot
live electrical circuits safely and in accordance
with accepted practice. FOR SAFETY’S SAKE,
if in doubt, please contact your distributor or
Presto Lifts at (800) 343-9322.
Before servicing the unit, read and understand
this entire section and the section entitled
“Operating Instructions.”
WARNING!
Before performing any maintenance
on this unit, lower the platform
completely.
If
the
platform
will
not
raise:
CAUTION!
If the platform will not raise, do not
continue to hold the Up button for
more than 2 or 3 seconds. You may
damage the pump.
1. The sensor and reflector are mounted at
the front of the unit, near the floor level. There
may be something blocking the beam of the
photo eye toe guard. The reflector may need
to be cleaned or replaced.
2. The load may be too heavy. Check the actual
weight of the load. The rated capacity of the
unit is shown on the name plate.
WARNING!
DON’T CHANGE THE SETTING OF
THE RELIEF VALVE. If you do change
the setting, this may cause a
hydraulic part to fail. The platform
may drop suddenly. Someone may be
hurt, and the unit and load may be
damaged. The hydraulic parts in the
lift are designed to handle a certain
amount of pressure. The relief valve
is set to relieve this pressure before
it becomes too great. The relief
