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 185 of 828

TM 9–2350–311–20–2

3–74

3–3

TROUBLESHOOTING — CONTINUED

e.

CAB HYDRAULIC SYSTEM — CONTINUED

(4)

HYDRAULIC PUMP MOTOR ON/OFF CYCLE

IS RAPID.

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Recharge system and observe pressure gage

during operation.

Does hydraulic pump come on when pressure drops

below 925 psi (6378 kPa) and shut off when pressure

reaches 1225 psi (8446 kPa)?

Charge main accumulator

nitrogen pressure (para

19–4).

Check nitrogen pressure in main accumulator (para

19–4).

Is pressure 500 to 550 psi (3448 to 3792 kPa)?

yes

no

yes

no

Notify support maintenance.

END OF TASK

A

yes

no

Replace pressure switch

(para 6–6). If malfunction

still persists, notify support

maintenance.

B

C

Check fluid level of hydraulic power pack (para 6–2).

Is fluid level low?

Add fluid (para 6–2).