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 167 of 828

TM 9–2350–311–20–2

3–56

Change 2

3–3

TROUBLESHOOTING CHART — CONTINUED

d.

ELEVATING SYSTEM — CONTINUED

(4)

CANNON DOES NOT ELEVATE OR DEPRESS

USING MANUAL ELEVATION SYSTEM OR

SYSTEM IS INEFFICIENT, BUT CANNON

WILL OPERATE UNDER POWER.

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

Materials/Parts

Hydraulic fluid OHT (item 21, Appx D)

References

TM 9–2350–311–10

Verify fault is corrected.

Continue normal opera-

tions.

1.

Loosen two hex nuts (1) at ports M1 and M2.

2.

Drain off pressurized fluids through manual

elevation tubes (2) until bubble free fluid flows.

3.

Tighten two hex nuts (1) to secure manual

elevation tubes (2).

4.

Rotate manual elevating hand pump

counterclockwise until movement is detected in

equilibrated elevating cylinder.

5.

Bleed elevating cylinders (para 6–3.1).

Does cannon move manually?

yes

no

CONTINUED ON NEXT PAGE

M1

M2

1

2

Verify fault is corrected.

Continue normal opera-

tions.

yes

no

A

Equilibrate elevating cylinder if necessary

(TM 9–2350–311–10).

Does system operate properly?

B