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 165 of 828

TM 9–2350–311–20–2

3–54

Change 2

3–3

TROUBLESHOOTING CHART — CONTINUED

d.

ELEVATING SYSTEM — CONTINUED

(3)

CANNON DOES NOT ELEVATE OR DEPRESS

SMOOTHLY.

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

References

TM 9–214

Inspect bearings in elevating cylinder eyes

(TM 9–214) and elevation pivot pins.

Do bearings or pins need replacement?

A

Check nitrogen precharge in primary accumulator

(para 19–5).

Is pressure abnormal?

Bleed air from equilibrated elevation hydraulic

system (para 6–3.1).

Will cannon elevate and depress smoothly?

yes

no

yes

no

B

C

Charge primary accumula-

tor (para 19–5). Perform

leak test (para 6–11).

Verify fault is corrected. Con-

tinue normal operations.

yes

no

Notify support maintenance.

CONTINUED ON NEXT PAGE

EQUILIBRATED ELEVATING CYLINDER

SECONDARY ACCUMULATOR

PRIMARY

ACCUMULATOR

BEARING

BEARING