Bosch Rexroth 31 Series Instruction Manual page 55

Table 14: Axial piston unit malfunction table
Malfunction
No or insufficient pressure
Pressure/flow fluctuations/
instabilities
Possible cause
Insufficient air bleeding of the hydraulic system
Faulty mechanical drive (for example, defective
coupling)
Drive power too low
Insufficient suction conditions, for example,
insufficient dimensioning of the suction line,
viscosity of the hydraulic fluid too high,
suction height too high, suction pressure
too low, foreign particles in the suction line,
impermissible filter in the suction line
Hydraulic fluid not in optimal viscosity range
Insufficient pilot pressure or control pressure
Malfunction of the control device or controller
of the axial piston unit
Control of the control device defective
Wear or mechanical damage to the axial
piston unit
Output unit defective (e.g. hydraulic motor or
cylinder)
Insufficient air bleeding of the hydraulic system
Insufficient suction conditions, for example,
insufficient dimensioning of the suction line,
viscosity of the hydraulic fluid too high,
suction height too high, suction pressure
too low, foreign particles in the suction line,
impermissible filter in the suction line
Valve and controller vibrate
Unstable control signal
Malfunction in the control devices or the
controller
Remedy
Fill the axial piston unit, suction line for the
hydraulic pump and the reservoir
Completely air bleed the axial piston unit and
hydraulic system
Check correct installation position
Contact machine/system manufacturer
Contact machine/system manufacturer
Machine/system manufacturer: check the
system, for example, optimize inlet conditions,
use suitable hydraulic fluid
Fill the suction line with hydraulic fluid
Remove foreign particles from the suction line
Machine/system manufacturer:
Check temperature range and use suitable
hydraulic fluid
Check pilot pressure or control pressure
Contact Bosch Rexroth Service
Contact Bosch Rexroth Service
Check control (contact machine/system
manufacturer or Bosch Rexroth Service)
Replace axial piston unit
Contact Bosch Rexroth Service
Contact machine/system manufacturer
Fill the axial piston unit, suction line for the
hydraulic pump and the reservoir
Completely air bleed the axial piston unit and
hydraulic system
Check correct installation position
Machine/system manufacturer: check the
system, for example, optimize inlet conditions,
use suitable hydraulic fluid
Fill the suction line with hydraulic fluid
Remove foreign particles from the suction line
Optimize the adjustment of the axial piston
unit and the pressure limitation in the hydraulic
system
Contact machine/system manufacturer or Bosch
Rexroth Service
Contact Bosch Rexroth Service
RE 92701-01-B/04.2018, A10VO, A10VSO Series 31, Bosch Rexroth AG
Troubleshooting 55/60