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 117 of 828

TM 9–2350–311–20–2

3–8

Change 2

3–3

TROUBLESHOOTING CHART — CONTINUED

a.

BREECH MECHANISM — CONTINUED

(2)

BREECH DOES NOT CLOSE COMPLETELY.

INITIAL SETUP

Tools

Artillery and turret mechanic’s tool kit

(SC 5180–95–CL–A12)

References

TM 9–2350–311–10

1.

File breech ring threads smooth (para 5–8) and

lubricate them (TM 9–2350–311–10).

2.

Attempt to close breech (TM 9–2350–311–10).

3.

Ensure cannon is between 300 to 400 mils.

Does the breech close completely?

1.

Clean breechblock and breech ring threads

(TM 9–2350–311–10).

2.

Inspect breech ring threads for burrs (para

5–8).

Are breech ring threads burred?

A

yes

no

Go to step C.

yes

no

Verify fault is corrected.

Continue normal opera-

tions.

CONTINUED ON NEXT PAGE

If breech is not closed completely, do not

attempt firing, as it may result in death or

injury to crew.

B

NOTE

Breech is completely closed when timing

marks aline.

WARNING