D-12 Blank - Bell OH-58A Technical Manual

D-6. SCOPE. This section lists pri-
mary, alternate, and expedient lubri-
cants and hydraulic fluids.
D-7. GENERAL.
a. The lubricants and hydraulic
fluids used in OH-58 systems and com-
ponents must have a compatible base
composition, as well as good additive
level. Being that the purpose of lubri-
cants and hydraulic fluids is to reduce
wear, support bearing loads, and provide
cooling, their chemical composition must
be compatible. In addition to lubri-
cating, hydraulic fluids must transmit
power and motion.
hydraulic fluids are mixed, there is a
tendency of a gel substance forming
within the system and ruining it.
Some lubricants will not with-
b.
stand OH-58 temperatures or loads for
extended periods of time.
lubricants do not contain the necessary
base properties for withstanding long
term performance; therefore, they are
recommended only as a last resort.
c. Expedient lubricants can cause
one of three problems.
(1) They may not allow proper
efficient operations because of improper
viscosity.
Section III. LUBRICANTS AND
If two incompatible
These type of
HYDRAULIC FLUIDS
(2) They may allow an increase in
wear because of improper viscosity.
(3) They may cause seals to swell
or create deposits because of improper
composition.
D-8. LUBRICANTS AND HYDRAULIC FLUIDS.
Table D-8 lists the primary lubricants
and hydraulic fluids which are used as
primary, alternate, and expedient uses
on the OH-58 helicopter.
CAUTION
Lubricating oil MIL-L-23699 shall
not be used in ambient tem-
peratures below minus 32°C/25°F.
NOTE
It is not advisable to mix
MIL-L-7808 and MIL-L-23699 oils,
except during an emergency. If
oils are mixed, the system should
be flushed within six hours. An
entry on DA Form 2408-13 is
required when the oils are mixed.
Hydraulic oils MIL-L-83282 and
MIL-L-5606 should not be mixed
except during an emergency. When
these oils are mixed with each
other or any other oil, a DA Form
2408-13 entry is required.
TM 55-1520-228-BD
APPENDIX D
D-11/(D-12 Blank)