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5.
Trouble Shooting
5.1
‘Passive’/spring applied, hydraulically released brakes
Brakes will not close
Brakes are free of pressure
YES
PU is working OK
Failure is caused by the brakes
NO
See section 5.2
– Power unit does
not release pressure
Brakes will not open
Brakes have sufficient pressure
(see hydraulic settings)
YES
PU is working OK
Failure is caused by the brakes
NO
See section 5.3
– Power Unit does
not reach release pressure
Brakes and PU work, but
behave unexpectedly
See section 5.4 - Other causes of
failure
5.2
Power Unit does not release pressure
Valve between brakes and tank
does not open.
Make sure that the valves from the
pump to the brakes are closed or the
pump is off (not running).
Failure in solenoid or power supply for solenoid.
Try manual override - if this releases the pressure, the problem is in
the coil or its power supply.
Try disconnecting the electrical plug from the coil - if this
releases pressure failure is in the power supply.
Defective or dirty (choked) valve or nozzle.
Before unscrewing a valve or other component you must ensure that
the pressure behind the valve is released.
If only one dump valve is present, you can release the pressure
through a test hose/Minimess hose.
5.3
Power Unit does not set/build up pressure
Oil level in tank is too low and/or oil
contamination outside the braking
system
If it is not immediately obvious where the leak is coming from, you
must refill the tank and start the pump, watching for leaking oil or
bubbles.
Motor is not running
Power supply failure or motor wrongly connected
Defective motor
Oil level too low or oil too hot (cut off by level or thermal switch) if
fitted
Defective pressure switch
Check motor protection setting and fuses.
Motor is running the wrong direction
Check rotation according to direction on motor, phases in the motor
junction box may be wrongly connected (swapped)
Motor is running but its speed
decreases before the system has
reached the correct pressure
Power supply has too low voltage
Defective motor
Motor power is too low for the pressure/volume needed to operate
the brake
Transmisiones FU Ibérica, S.L.
C/ África 17 · Polígono Industrial Can Mora · 08459 - Sant Antoni de Vilamajor · Barcelona · SPAIN
+34 93 268 18 33
fuiberica
@
fuiberica.com
www.fuiberica.com
