TM 10-3950-672-10
Oil too light may cause the following conditions in the system.
Excessive leakage.
Lower volumetric efficiency of the pump.
Increased component wear.
Loss of system pressure.
Lack of positive hydraulic control.
Lower overall efficiency.
Oil too heavy may cause the following conditions in the system.
System pressure drop.
Increases system temperature.
Sluggish system operation.
Low mechanical efficiency.
Higher power consumption.
The following oil viscosity characteristics are recommended.
80 to 180 SUS optimum at system operating temperature
60 SUS minimum at system operating temperature
7500 SUS maximum at starting temperature
90 Viscosity Index (VI), minimum
Pour point at least 20 (11 ) below start-up temperature
F
C
The following grades will usually meet the above viscosity requirements.
SAE Viscosity
Designation
Temperature
-10to 180 (-23to 82 )
5W-20
F
C
+10to 180 (-12to 82 )
10W
F
C
+ 10to 210 (-12to 99 )
10W30
F
C
Arctic Conditions. (Below 0 (-18 ). In general, petroleum-based fluids developed especially for low
b.
F
C
temperature service may be used with satisfactory results. However, certain fluids, such as halogenated
hydrocarbons, nitro hydrocarbons, and phosphate ester hydraulic fluids, might not be compatible with
hydraulic system seals and wear bands. If you are in doubt about the suitability of a specific fluid, check
with your authorized Grove distributor or Grove Customer Services.
Regardless of temperature and oil viscosity, always use suitable start-up procedures to ensure adequate
lubrication during system warm-up.
c.
Antiwear Additives. Excessive wear in the system may cause a loss in volumetric efficiency and may
cause shutdowns for maintenance. An efficient antiwear oil protects the components against rusting,
resists oxidation, and helps prevent wear.
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