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 736 of 828

TM 9–2350–311–20–2

19–28

Change 2

19–6 ACCUMULATOR ASSEMBLY, SECONDARY

This task covers:

a.

Service (Method One)

b.

Service (Method Two)

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Nitrogen charging kit (item 3, Appx H)

Materials/Parts

Dry nitrogen (item 22, Appx D)

Equipment Condition

Discharge hydraulic pressure (para 6–3.1)

a.

Service (Method One)

NOTE

Secondary accumulator assembly may be charged while mounted in cab.

1

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

2

Remove air valve cap (3) and loosen check valve nut (4) on valve (5) to release nitrogen precharge pres-

sure from secondary accumulator assembly (6).

3

Obtain nitrogen charging assembly (7) and remove gage (8).

WARNING

Secondary accumulator assembly contains high pressure nitrogen. Use caution when handling and

working with it.

4

Connect nitrogen charging assembly (7) to secondary accumulator assembly (6) and nitrogen charging cyl-

inder (9).

5

Attach angle valve (10) of nitrogen charging assembly (7) to valve (5), but do not tighten angle valve (10).

Close stop-check valve (11) and angle valve (12).

6

Open shutoff valve (13) on nitrogen cylinder (9).

7

Slowly open pressure regulator valve (14) until 3000 psi gage (15) shows 15–20 psi (103–138 kPa). Close

pressure regulator valve.

8

Open stop-check valve (11) on nitrogen charging assembly (7). Tighten angle valve (10) just before 3000 psi

gage (15) register 0 psi (0 kPa).

9

Loosen check valve nut (4) approximately one turn (2–1/4 turns is fully open).

10

Open pressure regulator valve (14) until 3000 psi gage (15) registers 1500

±

50 psi (10342

±

345 kPa).

11

Tighten check valve nut (4) when sound of nitrogen flow has stopped.

12

Close pressure regulator valve (14).