MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-11 - Manual (Page 61)

Replacing the Hydraulic Fluid
Model 505G2.07/.11 SilentFlo™ HPU 61
Replacing the Hydraulic Fluid
Replace the hydraulic fluid in the HPU reservoir whenever you have determined
that the hydraulic fluid is no longer suitable for use.
Recommended
equipment
• A transfer pump with a 10-micron filter (such as the Model 590.01 Fluid
Transfer Pump)
• ethanol or a similar cleaning solvent
• Lint-free cloths or manufactured rags
• A container for the used hydraulic oil and a small drain pan that will fit
underneath the drain plug
• A hydraulic fluid sampling kit (MTS part number 055-589-601).
• A new filter—see “Replacing the Return Line Filter”
Prerequisite Perform the procedure “Sampling the Hydraulic Fluid” to determine if the
hydraulic fluid should be replaced.
Identify and correct any sources of contamination.
Mixing different brands of hydraulic fluid can contaminate your system.
Contaminated hydraulic fluid can cause premature wear of the hydraulic
components in your system.
Do not mix different brands of hydraulic fluid. MTS Systems Corporation
recommends using ExxonMobil DTE-25 or Shell Tellus 46 AW hydraulic fluid.
Opaque fluid Indicates chemical breakdown Replace the fluid
Milky appearance Indicates water is present in the
fluid
Check the heat exchanger for damage.
Look for other water sources if the
water does not appear to be coming
from the heat exchanger.
Identify and correct the source of the
water leakage and replace the fluid if
necessary.
Sediment at the bottom of
the sample container (after
sample has stood
overnight) Indicates collapsed, ruptured, or
clogged filter(s)
Analyze the fluid and replace all filter
elements.
Clean the fluid or replace it as required
by the analysis.
Fluid Properties Problem What to Do
CAUTION