Bosch A4VG A4VG 32 Series Instruction Manual page 62

62/68 Troubleshooting
Table 13: Axial piston unit malfunction table
Malfunction
No or insufficient flow
Bosch Rexroth AG, A4VG Series 32, RE 92003-01-B/12.2015
Possible cause
Insufficient air bleeding of the hydraulic system
Faulty mechanical drive (e.g. defective coupling) Contact machine/system manufacturer
Drive speed too low
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.
Hydraulic fluid not in optimum viscosity range
Insufficient boost pressure
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
Remedy
Fill axial piston unit, suction line for the
hydraulic pump and the reservoir
Completely air bleed axial piston unit
and hydraulic system
Contact machine/system manufacturer
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
Machine/system manufacturer:
check temperature range and use
suitable hydraulic fluid
Check boost pressure
Contact Bosch Rexroth Service
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