MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-180 - Manual (Page 89)

7. If there still is any uncertainty regarding fluid quality, obtain another sample of the fluid and have it analyzed.
The fluid tests should include chemical analysis, particle count, and viscosity checks. Most oil companies
have facilities for performing these tests, or consult MTS Systems Corporation.
8. Remove the hose and valve assembly.
Appearance of Hydraulic Fluid Sample
What to Do Problem Fluid Properties
Analyze the fluid and replace as
required by the analysis. Indicates chemical breakdown or
the hydraulic fluid has been Dark colored fluid
allowed to rise above the
If the cause was overheating, flush
the entire system to remove varnish
maximum recommended
temperature (severe overheating)
or residue. Consult your MTS Field
Service Engineer to determine if
changes or adjustments to your
hydraulic system are required.
Analyze the fluid and replace as
required by the analysis. Indicates chemical breakdown or
the hydraulic fluid has been Burnt odor
allowed to rise above the
If the cause was overheating, flush
the entire system to remove varnish
maximum recommended
temperature (severe overheating)
or residue. Consult your MTS Field
Service Engineer to determine if
changes or adjustments to your
hydraulic system are required.
Replace the fluid Indicates chemical breakdown Opaque fluid
Check the heat exchanger for
damage. Indicates water is present in the
fluid Milky appearance
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.
Analyze the fluid and replace all filter
elements. Indicates collapsed, ruptured, or
clogged filter(s) Sediment at the bottom of
the sample container (after
sample has stood overnight)
Clean the fluid or replace it as
required by the analysis.
Series 505G2 SilentFlo™ Hydraulic Power Unit Product Information 89
Maintenance