TM-9-1240-401-34-P

TELESCOPE MOUNT M146: M118A2 AND M118A3; TELESCOPE MOUNT M145: M145A1; PANORAMIC TELESCOPE: M117 AND M117A2; FIRE CONTROL QUADRANT: M15; PERISCOPE: M42

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL

JULY 1993

TM-9-1240-401-34-P - Page 322 of 590

TM 9-1240-401-34&P

6-12. M42 PERISCOPE FINAL INSPECTION AND ADJUSTMENT- continued

d. SEALING INSPECTION

1

2

3

4

5

6

NOTE

There are currently 2 production models of the

M42 periscope in use. The earlier model re-

quires use of adapter 10552433 to attach

purging hose assembly. The later model does

not require the adapter.

Remove machine screw (1) or air valve cap (2) and

purging machine screw (3).

For early model M42 periscope only, attach

adapter (4) to inlet port (5).

Attach hose assembly (6) to adapter (4) or to purg-

ing valve stem (7).

Make sure pressure regulator valve (8) is closed

(fully counterclockwise). Open pressure regulator

valve (8) until low pressure gage (9) indicates 5 psi

(0.35 Kg/cm

2

).

a.

Maintain pressure for 5 minutes.

b. Close pressure regulator valve (8).

Apply adhesive to purging machine screw (3). In-

stall and tighten purging machine screw (3).

NOTE

Early production models go to step 6. Late

production models, go to steps 7,8, and 9.

Disconnect hose assembly (6) from inlet port (5).

a.

Remove adapter (4).

b. Apply adhesive to machine screw (1). Install

machine screw (1) in inlet port (5) and tighten.

6-12