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 111 of 590

TM 9-1240-401-34&P

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Secure pressure regulator (1) to a tank containing

pressurized nitrogen.

If registered pressure is 100 psi (689.48 kPa)

or less, obtain a replacement.

Open nitrogen tank valve (2) and observe pressure

gage (3). Gage should indicate pressure in nitro-

gen tank.

Adjust pressurized regulator by rotating handle (4)

until pressure gage (5) indicates 5 psi (34.47 kPa).

Close nitrogen tank valve (2).

Circuit card assembly must be removed from

M1 18A3 elbow telescope level assembly prior

to securing on fabricated leak test adapter

(ref. para 3-1 8).

Secure level assembly (6) to fabricated leak test

adapter (7) with four machine screws (8) and four

wing nuts (9).

Connect hose assembly (10)to the inlet port (11 )

on fabricated leak test adapter (7).

Open nitrogen tank valve (2).

Adjust handle (4) counterclockwise until 1 psi (6.89

kPa) is registered on the low pressure gage (5).

Maintain a 1-psig (6.89-kPa) pressure for 10 sec-

onds; then adjust handle (4) clockwise to the

closed position.

Disconnect hose assembly (10) from the inlet port

(11 ) and lay hose assembly (10) aside.

Completely immerse level assembly (6) and fabri-

cated leak test adapter (7) in a container of clear

water.

While level assembly is immersed inspect the

areas around the level (12) vial and lamp shell (13)

for air bubbles that indicate pressure leaks.

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