Bosch rexroth A4VSO 10 Series Instruction Manual page 73

table 18: Axial piston unit malfunction table
Malfunction
No or insufficient pressure
possible cause
Insufficient air bleeding of the hydraulic system Axial piston unit, suction line for the
Faulty mechanical drive (e.g. defective coupling) Contact machine/system manufacturer
Drive power 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, foreign particles
in the suction line, suction filter too small or
blocked, etc.
Hydraulic fluid not in optimal 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
Output unit defective (e.g. hydraulic motor
or cylinder)
RE 92050-01-X-B1/2019.08.23, Axial piston variable pump A4VSO, Bosch Rexroth AG
Troubleshooting
remedy
hydraulic pump and filling the reservoir
Completely air bleed the axial piston unit and
hydraulic system
Check correct installation position
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 foreign particles 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
Contact machine/system manufacturer
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