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 116 of 828

TM 9–2350–311–20–2

Change 2

3–7

1.

Slide firing group block to the left, firing position.

2.

Attempt to open breech.

Does breech open?

CONTINUED FROM STEP C

yes

no

Verify fault is corrected.

Continue normal opera-

tions.

Notify support

maintenance.

yes

no

END OF TASK

Verify fault is corrected.

Continue normal opera-

tions.

1.

Remove firing mechanism (TM 9–2350–311–10).

2.

Remove firing block assembly and firing

mechanism housing (TM 9–2350–311–10).

3.

Remove follower assembly from firing block

assembly (para 5–5).

4.

Inspect end follower for bent or damaged shaft

roller. If damaged, replace (para 5–5).

5.

Install firing mechanism housing, firing block

assembly, and firing mechanism assembly.

6.

Attempt to open breech.

Does breech open?

CONTINUED FROM STEP B OR C

yes

no

D

Verify fault is corrected.

Continue normal opera-

tions.

E

FIRING MECHANISM HOUSING

FOLLOWER

ASSEMBLY

FIRING

MECHANISM

FIRING

BLOCK

ASSEMBLY

FIRING

GROUP

BLOCK