MTS Series 505 SilentFlo Hydraulic Power Unit Model 505-11 - Manual (Page 63)

Appearance of Hydraulic Fluid Sample
Model 505.07/.11 SilentFlo™ HPU Maintenance 63
1. Operate the HPU until the hydraulic fluid is at normal operating temperature
(about 30 minutes).
2. Close the needle valve. Connect the hose valve assembly to the sample port
located on the hydraulic manifold on top of the HPU. (See illustration.)
3. Open the needle valve on the hose valve assembly and flush 1 liter (1 quart)
of hydraulic fluid though the sampling assembly. This fluid can be directed
to a waste container or back into the HPU reservoir.
4. Obtain a sample of the hydraulic fluid after flushing the valve hose
assembly.
A. Without closing the valve, quickly place the sample bottle into the fluid
stream (keep the sample bottle sealed until the sample is to be taken).
B. Fill the sample bottle (175 mL/6 oz) with fluid.
C. Close the valve on the hose valve assembly and cap the sample bottle.
5. Check the fluid qualities of the sample by comparing it to a small jar of
clean hydraulic fluid. Clean hydraulic fluid has an amber color.
See the table, “Appearance of Hydraulic Fluid Sample,” for unacceptable
fluid qualities.
6. 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.
7. Close the needle valve and remove the hose and valve assembly. Open the
needle valve.
Appearance of Hydraulic Fluid Sample
F LUID P ROPERTIES P ROBLEM W HAT TO D O
Dark colored fluid Indicates chemical breakdown or
the hydraulic fluid has been allowed
to rise above the maximum
recommended temperature (severe
overheating) Analyze the fluid and replace as
required by the analysis.
If the cause was overheating, flush the
entire system to remove varnish or
residue. Consult your MTS Field
Service Engineer to determine if
changes or adjustments to your
hydraulic system are required.
Burnt odor Indicates chemical breakdown or
the hydraulic fluid has been allowed
to rise above the maximum
recommended temperature (severe
overheating) Analyze the fluid and replace as
required by the analysis.
If the cause was overheating, flush the
entire system to remove varnish or
residue. Consult your MTS Field
Service Engineer to determine if
changes or adjustments to your
hydraulic system are required.