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

  TM-9-2350-311-20-2 - Page 730 of 828

TM 9–2350–311–20–2
19–22
Change 2
19–5 ACCUMULATOR ASSEMBLY, PRIMARY
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)
Hydraulic fluid, OHT (item 21, Appx D)
Equipment Condition
Discharge hydraulic pressure (para 6–3.1)
a.
Service (Method One)
NOTE
Primary 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 primary accumulator assembly (6).
3
Obtain nitrogen charging assembly (7) and remove gage (8).
WARNING
Accumulator contains high pressure nitrogen. Use caution when handling and working with it to
avoid injury.
4
Connect nitrogen charging assembly (7) to primary accumulator assembly (6) and nitrogen cylinder (9).
5
Attach angle valve (10) of nitrogen charging assembly (7) to valve (5), but do not tighten angle valve. 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 900
±
50 psi (6206
±
345 kPa).
11
Tighten check valve nut (4) when sound of nitrogen flow has stopped.
12
Close pressure regulator valve (14).


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