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 724 of 828

TM 9–2350–311–20–2
19–16
Change 2
19–3 ACCUMULATOR ASSEMBLY, MANUAL PUMP — CONTINUED
b.
Service (Method Two) — Continued
14
Open stop-check valve (9), allowing nitrogen to enter the accumulator (17) until gage (21) on the air pres-
sure gage assembly (18) reads 50 psi (345 kPa).
15
Close stop-check valve (9).
16
Open safety-relief valve (19) until all nitrogen is bled from accumulator (17), then close safety-relief valve.
17
Repeat steps 14 through 16 to remove all traces of moisture prior to charging system to full pressure. Re-
open stop-check valve (9).
CAUTION
Changing the system too fast will heat the dry nitrogen. This will give an inaccurate reading because
the pressure will decrease when the nitrogen cools possibly causing equipment to malfunction.
NOTE
Estimated time to charge system is 30 minutes or more. System should be charged at ambient tem-
perature of weapon use.
18
Open pressure regulator valve (14) slowly, turning clockwise until pressure on 3000 psi gage (15) registers
110 psi (758 kPa) at 70
°
F (21
°
C).
19
Open stop-check valve (9) slowly, allowing nitrogen to charge system.
WARNING
•
Failure to close check valve on main accumulator and pressure regulator valve could result in
injury from high pressure in hoses of nitrogen charging assembly and air pressure gage assem-
bly.
•
Failure to open safety-relief valve could result in injury from high pressure trapped in hoses of
nitrogen charging assembly and air pressure gage assembly.
20
Close angle valve (20) and nitrogen cylinder (2) shutoff valve (12). Let system remain idle for one hour after
charging.
21
Open safety-relief valve (19) to bleed pressure from nitrogen charging assembly (11) and air pressure gage
assembly (18).
22
Disconnect nitrogen charging assembly (11) and air pressure gage assembly (18) at angle valve (5).
23
Close pressure regulator valve (14) by turning counterclockwise.
24
Disconnect nitrogen charging assembly (11) from nitrogen cylinder (2) shutoff valve (12).
25
Close safety-relief valve (19).


Back to Top