Hydraulic System - Pfaff HV 1008 Operating Instructions Manual

Hydraulic hand stacker
English

Hydraulic System

The hydraulic system consists of the hydraulic aggregate with mounted-on lowering valve and safety valve, as
well as lifting cylinder with incorporated lowering brake valve.
The hydraulic system requires almost no maintenance apart from the rec. tests and the required oil change.
Prior to maintenance or repair relieve the pressure in the hydraulic system. Lower the fork completely and
remove the load.
If repair is unavoidable on the extended lifting structure, secure all parts (fork, mast, and cylinder) against
unintended lowering.
Do not run the hydraulic pump without oil!
Replace the pressure hose in case of damage or on demand, but at least after 6 years.
For oil changing, suck the oil out of the oil tank.
Ventilate the hydraulic system after oil change or on demand.
Ventilation may only be effected in unloaded state.
Ventilation Process
Slightly open the screw plug  at the top of the hydraulic cylinder.
Press the pushbutton (UP) until hydraulic oil discharges without bubbles.
Tighten the screw plug  before operating the lowering valve
Adjustment of the Lifting Chain
Adjust the chain length by tightening the tension nut  so that the load chain is
tightened when the load is in lowest position.
After adjustment fix nuts  and  by a lock nut.
At regular interval, check the lifting chains for fractures, scores, and marks of
wear
The permissible elongation must not exceed 3%.
Replace damaged chains or those elongated by more than 3%.
Malfunctions and their causes
Hydraulic system
Malfunction
The hydraulic stacker does not lift
– the pump does not work
The hydraulic stacker does not lift
the load, although the pump is
working perfectly
Loaded or unloaded, the
hydraulic stacker only lifts slowly
or not at all when the pump is
actuated
Raised load is lowered of its own
accord. Oil loss on hydraulic
cylinder.
The raised load is lowered too
slowly
Disposal:
After placing out of service, the hydraulic stacker parts must be disposed of or
recycled in accordance with legal provisions.
technische Änderungen vorbehalten
Cause
Lowering lever on the handle is in
the transporting position 
Insufficient oil in the tank
Load too heavy – the pressure
control valve is active
Lowering valve does not close any
more or the valve face is not sealed
because of dirt
Pressure control valve displaced or
valve face soiled
Hydraulic system pump is defective
Leakage in the hydraulic system
Lowering valve does not close any
more or the valve unit is not sealed
because of dirt
Incorrect valve set-up.
Sealing elements are worn
Temperature too low – the hydraulic
system oil is too thick
subject to change without notice
F 08.01.114
1
2
3
Elimination
Ventilate the hydraulic cylinder.
Refill with oil (while the fork is lowered)
Reduce load
Clean or replace
Adjust or clean valve
Repair or replace hydraulic system
pump!
Seal!
Clean or replace
Adjust lowering valve
Replace sealing elements
Find a warmer location
changements techniques sous réserve
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