MTS Model 506-62-72 Hydraulic Power Supply - Manual (Page 18)

3-6 Service
Replacing hydraulic fluid Perform this procedure to replace the hydraulic fluid. You will need a
Model 590.01 Fluid Transfer Pump or a pump which provides at least
10-micron filtration.
1. Turn off electrical power to the HPS. Remove the reservoir filler
cap assembly.
Drain
VW-G041E
Front View
2. Drain the hydraulic fluid into a container, while hot, through the
drain valve. Close the valve.
3. Then drain the oil from the entire system (such as from the hoses
and accumulators).
4. Dispose of the fluid according to company policy.
5. Remove the top plate from the reservoir.
6. Wipe the inside of the reservoir with a clean lint-free cloth.
Apply MOBILSOL A—a solvent for cleaning and flushing
hydraulic systems—to a clean lint-free cloth and again wipe the
reservoir. Immediately wipe away the solvent with a dry cloth.
7. Replace the high-pressure filter element. See Subsection 3.1.1.1.
8. Replace the low-pressure filter element. See Subsection 3.1.1.2.
CAUTION !
To avoid damage to the hydraulic system, follow these precautions:
Do not mix different brands of hydraulic fluid. This can create
contaminants. Ensure that the replacement hydraulic fluid is the same
brand and type as the fluid which was removed. Generally, an MTS
Hydraulic Power Supply contains Mobil DTE 25 hydraulic fluid.
Consult MTS before you use alternate fluids.
Use a transfer pump that provides 10-micron or better filtration. Most
commercial hydraulic fluids exceed the maximum amount of
contamination allowable in MTS hydraulic systems.
9. Use the transfer pump to fill the reservoir with fresh hydraulic
fluid.
10. To flush out the pipe line, connect a hose from the pressure line to
the return line of the last station, and operate the HPS at low
pressure for 2 - 4 hours.
11. Replace the high-pressure filter element if necessary (Subsection
3.1.1.1).