CLEANING, INSPECTION AND REPAIR
Section I. CLEANING
Use care in separating metals for cleaning. Observe
the following general cleaning precautions.
Petroleum solvent vapors are toxic. Provide
adequate ventilation for personnel using it.
a. Petroleum solvent (item 3, table 2-2) is the clean-
recommended for nonferrous parts (clean
ers for steel will damage nonferrous parts.) Do not use
rust preventives on
magnesium and aluminum parts.
b. Clean aluminum-coated steel parts with carbon re-
moval compound (item 17, table 2-2). Rinse the part
with water and dry with an air blast.
c. Clean steel parts with cresol base cleaning com-
pound (item 18, table 2-2). Rinse the part thoroughly
with hot water. Coat parts with a compound of one part
rust preventive (item 19. table 2-2) and the parts oil
(item 20, table 2-2).
7-2. Cleaning Engine Exterior Surfaces
Flush or spray wash external surfaces with petroleum
solvent (item 3A, table 2-2) to remove grease. oil. and
dirt. Ensure that all openings are plugged or covered be-
Engine thermocouples should never be satu-
rated or sprayed with cleaning solvents Liq-
uid cleaning solvents will penetrate the po-
rous magnesium oxide insulation. Engine
heat will vaporize the solvents leaving a resi-
due containing carbon which causes a low
resistance to ground.
7-3. Compressor Cleaning to Restore Lost
Allow the engine to cool for a minimum of 45
minutes prior to spraying the compressor.
Mandatory cooling period is required to
prevent warpage to internal engine compo-
Buildup of dirt in the compressor can result in a seri-
ous loss of engine power and performance. Lost perfor-
mance may be restored by flushing the installed engine
with a water/solvent solution as follows:
Methanol is flammable; it should not be
used if the ambient temperature is above
4°C (40°F), its vapor is harmful; it could be
fatal or cause blindness if swallowed. Keep
it away from open flame and avoid pro-
longed breathing of the vapor.
Once the cleaning procedure is started, it must
be carried through to completion without
delay. At ambient temperatures below 4 C
(40°F) and above -29°C (-20°F), use a 40 per-
cent Methanol (item 34. table 2-2),60 percent
water mixture, in place of fresh water. The
temperature of the wash solution should not be
below 4°C (40°F), ideally it should be be-
tween 21-26°CC (70-80°F). T O avoid spray-
ing concentrated Methanol. which is combus-
tible. mix the solution thoroughly.
B&B 3100 (MIL-C-85704, Type I) is the pri-
mary cleaner for Army turbine engines and re-
mains an approved cleaner for locales where
restrictions permit. Engine
cleaners that conform to MIL-C-85704. Type
II and Type IIA are also acceptable engine
cleaners and meet EPA environmental require-
ments. Continue use of B & B 3100 where not
restricted. Where restrictions apply use
MIL-C-85704. Type II and Type IIA cleaners.
Approved Type II and Type IIA cleaners shall
be used in accordamce with the existing wash-
ing procedure. Type IIA cleaners do not require
dilution with water. Both types of cleaners are
less effectzive than Type I cleaners. Therefore
more frequent engine washes may be required
to achieve satisfactory results.