Troubleshooting 51/56
RE 91706-01-B/09.2015, A10VER Series 52,
Bosch Rexroth AG
14.2 Malfunction table
Table 13: Axial piston unit malfunction table
Fault
Possible cause
Remedy
Unusual noises
Insufficient air bleeding of the hydraulic system
Fill axial piston unit, suction line for the
hydraulic pump and the reservoir
Completely air bleed axial piston unit and
hydraulic system
Check correct installation position
Output speed too high
Machine/system manufacturer: reduce
output speed
Improper mounting of the axial piston unit
Check the mounting of the axial piston unit
according to the specifications of the machine/
system manufacturer (observe tightening
torques)
Improper mounting of attachments, hydraulic
lines or improper installation of the coupling
Mount attachments according to the
information provided by the coupling or fitting
manufacturer
Mechanical damage to the axial piston unit
(e.g., bearing damage).
Replace axial piston unit
Contact Bosch Rexroth Service
Increased, unusual vibration
Bearings worn
Contact Bosch Rexroth Service
Reversing not possible
Hydraulic fluid too viscous
Check hydraulic fluid temperature on the high-
pressure side
Time-delay orifice clogged
Repeat reversing process (contact machine/
system manufacturer or Bosch Rexroth Service)
Defective solenoid, connector or lines
Make sure the solenoid/plug is properly
connected. Make sure the electrical control
functions properly.
No or insufficient pressure
Insufficient air bleeding of the hydraulic system
Fill axial piston unit, suction line for the
hydraulic pump and the reservoir
Check correct installation position
Faulty mechanical output drive (e.g., defective
coupling)
Contact machine/system manufacturer
Drive power too low
Contact machine/system manufacturer
Malfunction in the axial piston unit control
device or controller
Contact Bosch Rexroth Service
Control of the control device defective
Check control (contact machine/system
manufacturer or Bosch Rexroth Service)
Wear or mechanical damage to the axial
piston unit
Replace axial piston unit
Contact Bosch Rexroth Service
Drive unit defective (e.g., hydraulic pump)
Contact machine/system manufacturer
Pressure/flow fluctuations or
instabilities
Insufficient air bleeding of the hydraulic system
Fill axial piston unit, suction line for the
hydraulic pump and the reservoir
Completely air bleed axial piston unit and
hydraulic system
Check correct installation position
Unstable control signal
Contact machine/system manufacturer or
Bosch Rexroth Service
Malfunction in the control devices or the
controller.
Contact Bosch Rexroth Service