REXROTH A4VSG - Page 55

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Hyquip Limited New Brunswick Street Horwich Bolton Lancashire BL6 7JB UK
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Troubleshooting 55/60
RE 92100-01-B/09.2012, A4VSG Series 10, 11 and 30, Bosch Rexroth AG
Table 13: Axial piston unit malfunction table
Fault Possible cause Remedy
No or insufficient pressure Faulty mechanical drive
(e.g. defective coupling).
Machine/system manufacturer.
Drive power too low. Machine/system manufacturer.
Insufficient suction conditions, e.g. air in
the suction line, insufficient diameter of the
suction line, viscosity of the hydraulic fluid
too high, suction height too high, suction
pressure too low, contaminants in the
suction line.
Machine or system manufacturer
(e.g. optimize inlet conditions, use suitable
hydraulic fluid).
Completely air bleed axial piston unit,
fill suction line with hydraulic fluid.
Remove contaminants from the suction line.
Inadequate supply at port E. Examine boost oil supply, e.g. ensure
function of boost pump, check filter.
Hydraulic fluid not in optimum viscosity
range.
Use suitable hydraulic fluid
(machine/system manufacturer).
External control of the control device
defective.
Check external control
(machine/system manufacturer).
Insufficient pilot pressure or control
pressure.
Check pilot pressure or control pressure,
contact Bosch Rexroth Service.
Malfunction of the control device or
controller of the axial piston unit.
Contact Bosch Rexroth Service.
Wear of axial piston unit. Exchange axial piston unit,
contact Bosch Rexroth Service.
Mechanical damage to the axial piston unit
(e.g. bearing damage).
Exchange axial piston unit,
contact Bosch Rexroth Service.
Output unit defective (e.g. hydraulic motor
or cylinder).
Machine/system manufacturer.
Pressure/flow fluctuations Axial piston unit not or insufficiently air bled. Completely air bleed axial piston unit.
Insufficient suction conditions, e.g. air in
the suction line, insufficient diameter of the
suction line, viscosity of the hydraulic fluid
too high, suction height too high, suction
pressure too low, contaminants in the
suction line.
Machine or system manufacturer
(e.g. optimize inlet conditions, use suitable
hydraulic fluid).
Completely air bleed axial piston unit, fill
suction line with hydraulic fluid.
Remove contaminants from the suction line.
Inadequate supply at port E. Examine boost oil supply, e.g. ensure
function of boost pump, check filter.
Excessive hydraulic fluid temperature and
case temperature
Excessive inlet temperature at the axial
piston unit.
Machine or system manufacturer:
inspect system, e.g malfunction of the
cooler, insufficient hydraulic fluid in the
reservoir.
Malfunction of the pressure control valves
(e.g. high-pressure relief valve, pressure
cut-off, pressure controller).
Contact Bosch Rexroth Service.
Malfunction of the flushing valve Contact Bosch Rexroth Service.
Wear of axial piston unit. Exchange axial piston unit,
contact Bosch Rexroth Service.
Instability/vibrations Setpoint value not stable. Machine/system manufacturer.
Resonance in the reservoir line. Machine/system manufacturer.
Malfunction of the control devices or the
controller.
Contact Bosch Rexroth Service.