Troubleshooting 63/68
RE 92003-01-B/12.2015, A4VG Series 32,
Bosch Rexroth AG
Table 13: Axial piston unit malfunction table
Malfunction
Possible cause
Remedy
No or insufficient pressure
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
Faulty mechanical drive (e.g. defective coupling) Contact machine/system manufacturer
Drive power too low
Contact machine/system manufacturer
Insufficient suction conditions, e.g. insufficient
dimensioning of the suction line, viscosity of
the hydraulic fluid too high, suction height too
high, suction pressure too low, contaminants in
the suction line, suction filter too small, etc.
Machine/system manufacturer: check
the system, e.g. optimize inlet conditions,
use suitable hydraulic fluid
Fill the suction line with hydraulic fluid
Remove contaminants from the suction line
Check the filter system and change the
filter as necessary
Hydraulic fluid not in optimum viscosity range
Machine/system manufacturer:
check temperature range and use
suitable hydraulic fluid
Insufficient boost pressure
Check boost pressure
Contact Bosch Rexroth Service
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
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
Output unit defective
(e.g. hydraulic motor or cylinder)
Contact machine/system manufacturer
