TM-9-2350-311-10

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; OPERATOR’S MANUAL

NOVEMBER 1994

TM-9-2350-311-10 - Page 409 of 775

TM 9-2350-311-10

3-4

TROUBLESHOOTING — CONTINUED

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

CANNON

15.

JERKY RECOIL; EXCESSIVE RECOIL FORCE; EXCESSIVE RECOIL TRAVEL AT HIGH ANGLE OF FIRE.

Step 1.

Step 2.

Step 3.

Step 4.

Check for air in variable recoil hydraulic system and buffer assembly.

Bleed variable recoil assembly and buffer assembly (item 11, Appx G).

Check replenisher accumulator assembly level.

Fill as necessary (item 10, Appx G).

Check to see if cradle sleeve bearings need lubrication.

If necessary, lubricate (item 32, Appx G).

Check recuperator assembly pins.

If pins extend more than 3/4 inch (19.05 mm), add hydraulic fluid (item 12, Appx G). If fault

continues, notify unit maintenance.

16.

PRIMER DOES NOT FIRE.

Step 1.

Step 2.

Step 3.

Step 4.

Follow misfire instructions before opening breechblock (para 2–15).

Check primer for firing pin dent.

Replace primer if dented (para 2–12.5).

Check firing pin for mushrooming, breakage, or burrs.

NOTE

If firing pin is defective, replace on M109A5 howitzers or notify unit maintenance

for replacement on M109A2/M109A3/M109A4 howitzers.

If defective, notify unit maintenance or replace firing pin (para 3-6.8).

Check for bent, burred, or worn firing mechanism parts.

If necessary, notify unit maintenance to replace defective firing mechanism parts (para 3-6.8).

Check nut on spindle assembly for cross-threading caused by carbon deposits.

Clean or replace nut on spindle assembly (para 3-6.8). If problem persists, notify unit maintenance.

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