Bosch Rexroth A4VG 35 Series - Filling the Axial Piston Unit

Commissioning 45/64
RE92035-01-B/2019-11-25, A4VG Series35, Bosch Rexroth AG
8.1.1 Filling the axial piston unit
Professional filling and air bleeding is necessary to prevent damage to the axial
piston unit and to maintain proper function.
Usually, the cleanliness level of commercial hydraulic fluids is insufficient for the
requirements of our components. These hydraulic fluids must be filtered during
filling using an appropriate filter system to minimize solid particle contamination
and water in the system.
Use only a hydraulic fluid that corresponds to the following requirements:
You can find details on the minimum requirements for hydraulic fluids in
BoschRexroth datasheets 90220, 90221, 90222, and 90225. The titles of the
datasheets can be found in Table 1 "Required and supplementary documentation"
on page5.
BoschRexroth evaluates hydraulic fluids on the basis of the Fluid Rating
according to datasheet90235. For hydraulic fluids which have been positively
evaluated in the Fluid Rating, please refer to datasheet90245 "BoschRexroth
fluid rating list for Rexroth hydraulic components (pumps and motors)".
Thehydraulic fluid should be selected so that the operating viscosity in the
operating temperature range is within the optimum range
(ν
opt
;seeselectiondiagram in the datasheet92035).
To ensure the functional reliability of the axial piston unit, the hydraulic fluid must
have a min. cleanliness level of 20/18/15 as defined in ISO 4406. At a hydraulic fluid
viscosity of less than 10mm²/s (e.g.due to high temperatures during short-term
operation) at the drain port, a cleanliness level of at least 19/17/14 according to
ISO4406 is required. You can find details on the permissible and optimal viscosities
and admissible temperatures in datasheet92035.
Proceed as follows to fill the axial piston unit:
1. Place a drip tray under the axial piston unit to collect any hydraulic fluid that may
leak.
NOTICE! Contaminated hydraulic fluid!
The cleanliness levels of commercial hydraulic fluids are usually insufficient for the
requirements of our components.
▶ Use a suitable filter system to filter hydraulic fluids during filling to minimize solid
particle contamination and water in the hydraulic system.
2. Fill and air bleed the axial piston unit viathe appropriate ports; seechapter 7.3
"Installation position" on page32. Also fill the hydraulic lines of the system.
Procedure