Hardi COMMANDER 4500, Instruction Book

Page: 146 / 170

7 - Fault Finding
144
Hydraulic System, Z-version
TWIN System - Blower
FAULT PROBABLE CAUSE CONTROL / REMEDY
No boom movements when activated. Insufficient hydraulic pressure. Check oil pressure.
Check tractor hydraulic oil level.
Insufficient oil supply. Oil flow must be 7-24 gal/min (depending on the
equipment on the sprayer).
Check tractor hydraulic oil level.
The operator has interrupted the boom folding by
releasing the folding button in the tractor for more
than 30 seconds. A built-in timer automatically
removes the oil pressure in the yaw dampers 30
seconds after activating a folding button. Unfold the boom completely. Start folding again
without letting go of the activated folding buttons
for more than 30 seconds at a time, until the folding
is completed.
Blown fuse(s). Check / replace fuse in junction box.
Bad / corroded electrical connections. Check / clean connections, multi plugs etc.
Insufficient power supply. Voltage on activated solenoid valve must be more
than 8 volts.
Use wires of at least 10 awg. for power supply.
Defective relay / diodes in junction box. Check relays, diodes and soldering at PCB in junction
box. LED diodes indicate boom functions.
Clogged restrictors in bypass block. Remove and clean restrictors in bypass block (See
hydraulic diagram). Change hydraulic oil + filter.
Wrong polarity. Check polarity. Red positive (+), black negative (-).
ParaLift lock does not lock.
Boom lift raises to max. position, when tractor
hydraulics are engaged.
Back pressure in return line exceeds 220 psi (15 bar). Connect the return line with a free flow to hydraulic
oil reservoir.
Divide return line in two and lead return oil back to
reservoir via two spool valves.
Oil heats up in Closed Center systems. Bypass valve does not close properly. Check / close (screw in) by-pass valve.
Internal leaks in flow regulator. Replace flow regulator O-rings and backup rings.
Replace flow regulator.
Individual hydraulic piston does not move. Clogged restrictor. Dismantle and clean restrictor.
FAULT PROBABLE CAUSE CONTROL / REMEDY
Max. revolutions cannot be obtained. Tractor’s PTO speed is lower than 1000 rpm
(reading failure on tractor meter). Check tractor’s PTO speed (rpm).
Check tractor meter.
Feed pressure too low. Adjust feed pressure to correct setting.
Pump/motor is worn. Get transmission checked by your HARDI® dealer.
Noisy blower transmission. Wrong oil quality (foam). Change oil to correct quality.
Feed pressure too low. Adjust feed pressure.
Oil filter is clogged (pressure gauge indicator is in
the red area). Change oil filter.
Formation of foam in oil tank. Pump/motor is worn. Get transmission checked by your HARDI® dealer.
Wrong oil quality (foam). Change oil to correct quality.
Mixture of hydraulic oil and other oil quality (e.g.
universal oil). Change oil to correct quality.
Oil change interval not kept. Change oil to fresh, clean oil of correct quality.
Leak on the pump suction line. Check hydraulic pump suction line for leaks.
Blower speed will not stay at adjusted level. No signal from speed sensor at the blower. Check the wire connection between sensor and
actuator for damages.
Bad / corroded electrical connections.
Blower speed control does not start up. Blown fuse(s). Check power supply and fuse.
Oil leak from pump / motor shaft seal (the seal is
pressed out). Drain hoses from motor / pump housing is blocked. Check the drain hose(s) for bends, damages and
proper attachment.
Too much pressure in pump/motor housing (pump
/ motor worn). Get transmission checked by your HARDI® dealer.