Section IV. ASSEMBLY OF FACEPIECE GROUP

TM 3-4240-212-14&P

Malfunction

test or inspection

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

a. Removal. Unfasten head-harness straps (1, fig B-

assembly

1) from facepiece buckles.

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