Service Manual and
Axial Piston Motors Series 20
Repair Instructions
L1003443
• Rev BA • Jun 2014
11
The filter element must be exchanged as soon as the pressure drops below 0.75 bar [10.9 psi]
absolute (-0.25 bar [-3.6 psi]) when the transmission is at normal operating temperature. The filter
must also be exchanged each time the pressure fluid is changed. Filtration grade = 10
µ
m [394
µ
inch]
nominal.
Under normal operating conditions, the oil should be changed at the following intervals:
The first oil change should be carried out after max. 80-100 hours of operation but at the latest one
year after first-time operation. The second change should take place after max. 500 hours of
operation but at the latest one year after the first change.
Thereafter, the oil should be changed at least every 1000 hours of operation or at least once a year.
To change the oil, the used fluid must be drained off when the system is at operating temperature!
Remove any residual dirt or sludge from the reservoir!
In extremely dusty atmospheres, the intervals between oil changes must be correspon dingly
shortened.
Oil samples should be taken every 500 hours of operation. To do this, take approx. 0.5l of oil from a
point on a level with the inlet (suction) connection. Fill the sample into a closable container that is
free of residues.
Have the oil examined for serviceability by Danfoss, by Oil Manufacturer or by an appropriate
institution.
Important:
Use only recommended oils! (See
Fluid Manufacturers, Technical Information
). It is not
permissible to mix oils.
Carry out a leak test on the transmission (inlet line, filter, pipe and hose lines and connec tions, valves,
control elements, pump and motor) giving due consideration to the service life of the transmission,
environmental protection and reduction of oil consumption.
Tighten up any leaking joint and other connections while the system is not under pressure.
Make certain that the air filter for ventilation of the oil reservoir is regularly cleaned, since the input
pressure may be affected if it is dirty. If there is an oil cooler, the cooler surface should be kept free
from contamination. On units which have hose couplings on the connecting pipes, contamination of
any sort must be avoided. Cotton rags or lint cleaning cloths may not be used for cleaning. Use only
lint-free materials.
When changing the oil, be sure the area around the filler cap is free from foreign objects. The oil,
which can be kept clean by using a filter cloth, should be added by means of a clean funnel.
The level of the oil should be checked daily using the gauge glass. In case of loss of oil, the leak must
be rectified.
Important:
Use only recommended fluids! (See
Fluid Manufacturers, Technical Informa tion.)
It is not
permissible to mix.
HLP - hydraulic fluids according to DIN 51524
ATF - automatic transmission fluids type A, SUFFIX A
HD - SAE motor oils
see Danfoss manual
Fluid Manufacturers, Technical Information.
Inlet Filter
Changing the oil
Leak Test
Cleanliness
Checking the oil level
Recommended oils
System Maintenance
