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TM 5-4120-361-14
cloths to protect the gas charge in ex-
pansion valve bulbs and capillary tub-
ing.
1.
Brazing operations should
be carried out using approved
eye protection equipment and
rods not containing cadmium.
2.
Certain brazing operations
may require mechanical
ventilation.
3.
Local preventive medicine
personnel should be queried
if doubt exists as to rod
composition or ventilation
requirements.
c. Brazing. Braze copper-to-copper
joints with silver solder type 3, 4 or
6A specification QQ-S-561 and copper-to-
brass or copper-to-steel with type 4 or
6A specification QQ-S-561 per MIL-B-
7883.
Solder melting point is 1160°F
(625°C).
All brazed or soldered joints
shall be made with an atmosphere of in-
ert gas to prevent internal oxidation.
5-8.
Insulation and Gaskets.
Replace dmaged insulation and gas-
kets.
Cement loose insulation.
5-9.
Hardware.
Replace any damaged screws, washers,
lockwashers or nuts.
use screws of cor-
rect length to hold parts securely. In
some applications screws that are too
long may hit bottom before the head is
tight against part it is to hold or may
cause damage to the threads or other
parts.
5-10.
Shims.
Be sure to remove all shims where
used.
Keep shims together and identify
them as to location.
5-11.
Repairing Damaged Threads.
Damaged threads should be repaired by
use of a thread restorer or by chasing
in a lathe.
Internal threads should be
repaired with a tap of the correct size.
If threads cannot be satisfactorily re-
paired, replace the part.
Drill out and
replace blind rivet nuts having defec-
tive threads.
5-12.
Repair of Damaged Machined and
Polished Surfaces.
Smooth rough spots, scores, burrs,
galling, and gouges from damaged ma-
chined and polished surfaces so that
part will efficiently perform its normal
function.
The finish of the repaired
part is to approximate that of the orig-
inal finish.
In perfoming any of these
operations, critical dimensions must not
be altered.
5-13.
Removal of Rust or Corrosion.
Remove corrosion from all parts of ma-
terial.
To remove rust or corrosion,
use wire brush, abrasive cloth, sand
blast, vapor blast equipment, or rust
remover except on highly polished sur-
faces.
On these surfaces, buffing or
the use of crocus cloth is recommended.
5-14.
Tubes and Fittings.
Check tubes and fittings for cracked
or split condition.
Check tubing for
kinks.
Replace defective fittings. Re-
place damaged tubing with tubing of same
size.
Take care in making bends in tub-
ing to prevent kinking of tubing.
All
tubing and fittings must be completely
clean on inside prior to installation.
5-15.
Valves.
Valves and other parts should be
handled carefully to prevent damage.
Capillary tubes must be handled very
carefully to prevent kinking of the
tubes.
Section IV.
REMOVAL AND INSTALLATION OF MAJOR COMPONENTS AND ASSEMBLIES.
5-16.
General. (See WARNING inside
ect support and general support mainte-
front cover.)
nance.
The refrigerant piping and
valves cannot be removed as a unit, and
This section covers removal of all
only those parts that require replace-
major assemblies of the air conditioner
ment should be removed. Removal and in-
which are the responsibility of the dir-
stallation instructions for individual
5-7
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