TM-9-2350-311-20-2

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR CAB, ARMAMENT, SIGHTING AND FIRE CONTROL, ELEVATING AND TRAVERSING SYSTEMS AND ASSOCIATED COMPONENTS

DECEMBER 1993

TM-9-2350-311-20-2 - Page 740 of 828

TM 9–2350–311–20–2

19–32

19–6 ACCUMULATOR ASSEMBLY (SECONDARY) — CONTINUED

b.

Service (Method Two) — Continued

NOTE

Estimated time required to charge system is 30 minutes or more. System should be charged at am-

bient temperature of weapon.

18

Open angle valve (12) slowly, allowing dry nitrogen to charge system. Raise pressure in 100 psi (690 kPa)

increments until gage (8) on air pressure gage assembly (16) stabilizes at 1500

±

50 psi (10342

±

345 kPa)

at 70

°

F (21

°

C).

WARNING

Failure to close check valve nut on secondary accumulator assembly could result in injury to per-

sonnel from high pressure gas.

19

Close check valve nut (4) and shutoff valve (13). Let system remain idle for at least one hour after charging.

WARNING

Failure to open safety-relief valve could result in injury from high pressure trapped in hoses.

20

Open safety-relief valve (17) to bleed pressure from nitrogen charging assembly (7) and air pressure gage

assembly (16).

21

Disconnect nitrogen charging assembly (7) and air pressure gage assembly (16) at angle valve (10).

22

Close pressure regulator valve (14) by turning counterclockwise.

23

Disconnect nitrogen charging assembly (7) from shutoff valve (13).

24

Close safety-relief valve (17).

25

Open check valve nut (4).

26

Slowly open safety-relief valve (17), reducing pressure to 1500 psi (10342 kPa). Close safety-relief valve.

27

Close check valve nut (4) by turning clockwise.

28

Open safety-relief valve (17).

29

Disconnect air pressure gage assembly (16) from valve (5).

30

Install air valve cap (3) on valve (5).

31

Install two cap screws (1) and retaining strap (2).