TM 3-4240-212-14&P
Malfunction
Malfunction
test or inspection
test or inspection
corrective action
corrective action
3. TIMER DOES NOT RING
Defective timer
Step 4 Canister loose
Replace /para 4-10)
Tighten handwheel
4. FACEPIECE GROUP LEAKS
2. BREATHING RESTRICTED
Defective component
Defective facepiece valve assembly
Repair or notify higher maintenance
Notify higher maintenance
Section IV. ASSEMBLY OF FACEPIECE GROUP
(2) Unwrap tape from tube.
4-5.
Head Harness
(3) Separate breathing tube from facepiece valve
assembly
b. Disassembly.
b. Installation.
(1) Loosen hose clamp (15) that attaches
(1) Place new head harness in facepiece with
breathing tube to hose insert (17) by lifting latch on clamp
rough side toward facepiece
with screw-driver.
(2) Position straps marked NECK at bottom of
(2) Unwrap tape from tube.
facepiece, straps marked SIDE at temple positions, and
(3) Separate hose insert from breathing tube. It
strap marked FRONT at top of facepiece
may be necessary to pry tube from insert to break
(3) Fasten straps to corresponding facepiece
adhesive applied during assembly.
buckles.
(4) Remove union nut (16} and gasket (18) from
hose insert.
4-6.
Lens and Lens Clamp
c. Inspection
a. Removal
(1) Inspect components for deterioration or
(1) Remove screw and sleeve nut from lens
damage
clamp (6, fig B-1).
(2) Replace faulty components.
(2) Separate ends of clamp far enough to clear
d. Assembly.
lens and remove clamp
(1) Install union nut on hose insert.
(3) Remove lens (5) by stretching edge of
(2) Slide hose clamp (15) on end of breathing
facepiece socket away from lens and working lens free of
tube.
socket.
(3) Apply a thin film of rubber adhesive MIL-A-
b. Installation
5092A to outside of hose-insert end that fits in tube.
(1) With convex surface of lens facing toward
(4) Slide hose Insert into end of breathing tube as
front of facepiece, insert lower edge of lens in facepiece
far as it will go.
socket.
(5) Wrap the end of the breathing tube that has
(2) Work lens into facepiece socket by stretching
the insert with one layer of adhesive tape.
edge of socket until lens is firmly seated.
(6) Place hose clamp over adhesive tape and
(3) Fit lens clamp around facepiece socket and
tighten.
position as shown in figure B-1.
(7) Install gasket on hose insert.
(4) Install sleeve nut and screw in lens clamp.
e. Installation
(5) Tighten screw m sleeve nut. Take care not to
(1) Moisten inner end of breathing tube with water
distort clamp or damage facepiece.
Do not use oil.
4-7.
Breathing Tubes (Exhalation and Inhalation)
(2) Slide hose clamp (12) on end of breathing
a. Removal.
tube.
(1) Loosen hose clamp (12, fig.
B-1) that
(3) Insert appropriate branch of facepiece valve
attaches the breathing tube to the facepiece valve
assembly In breathing tube.
assembly by lifting latch on clamp with screwdriver.
(4) Wrap end of breathing tube with one layer of
adhesive tape.
(5) Place hose clamp over adhesive tape and
tighten clamp.
4-3
