Maintenance
62 Series 505G2 SilentFlo™ Hydraulic Power Unit
Important: To prevent problems with inconsistent and inferior fluids, MTS recommends only
ExxonMobil DTE 25 or Shell Tellus 46 to its customers.
Procedure
Perform the following checks of the hydraulic fluid weekly. If you suspect contamination of the hydraulic
fluid, take a sample and have it analyzed.
1. Check the fluid level in the HPU sight gage to verify the fluid level is correct.
l A low level can indicate a leak. If necessary, add enough fluid to bring the reservoir
level up to the proper operating level.
l A high level can indicate water contamination from the heat exchanger.
2. Check the hydraulic fluid color. Clean hydraulic fluid is amber in color.
Keep a sample of brand-new hydraulic fluid in a clean glass container for comparison. A
change in color can mean that the fluid is contaminated or that it has broken down chemically.
Refer to the table, “Appearance of Hydraulic Fluid Sample,” if the hydraulic fluid appears
different than the clean sample.
3. Check the smell of the hydraulic fluid. Burnt-smelling hydraulic fluid can indicate a chemical
breakdown.
If you detect a distinct change in the smell of hydraulic fluid, have it chemically analyzed by the
manufacturer.
4. Keep records of the maximum reservoir temperature.
High operating temperatures can cause the fluid to break down. If your records indicate a
pattern of overheating, consult your MTS Field Service Engineer to determine if changes or
adjustments to your hydraulic system are required.
5. Check and adjust the hydraulic fluid delivery system so that:
l Hydraulic fluid temperature stabilizes within acceptable limits when the HPU is
operating at high pressure.
l Pressure line reading is maintained at 21 MPa (3000 psi) maximum static value.
l Maximum drain line back pressure is limited to 0.1 MPa (15 psi).
If you need to adjust the water-regulating valve, overtemperature switch or pressure control valves,
see the procedure for Changing the Water Flow.
Replacing the Return Line Filter
The filter element of the HPU should be replaced for the following reasons:
l When the dirty-filter indicator lights
l Whenever the hydraulic fluid is changed
l The maximum interval recommended by the filter manufacturer has passed (1000 hours or 6
months)
To Next Page
Loading...
Need help?
General