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 332 of 828

TM 9–2350–311–20–2

6–16

Change 2

6–3.1 EQUILIBRATED ELEVATION MECHANISM ASSEMBLY — CONTINUED

b.

Bleeding

WARNING

Bleed valves may have high pressure when first opened. Use caution when opening valves to avoid

injury.

1

Open bleed valves (8 and 9) on elevating cylinder (10).

2

Place ELEVATION CONTROL switch (3) to NO. 1 MAN position.

3

Pull back slowly on assistant gunner’s control handle (11) until air-free hydraulic fluid flows from bleed valve

(8). Then close bleed valve.

4

Push forward slowly on assistant gunner’s control handle (11) until air-free hydraulic fluid flows from bleed

valve (9). Then, close bleed valve.

5

Refill hydraulic power pack reservoir to FULL AFTER PUMPING mark (12) (para 6–3c.).

6

Ensure equilibrator valve knob (4) is closed on equilibrator manifold assembly (7). Make sure that howitzer

tube is fully depressed.

7

Open rear bleed valve (13) on elevating cylinder (10).

8

Pump equilibrator hand pump (14) until air-free hydraulic fluid flows from rear bleed valve (13). Then close

rear bleed valve.

12

3

14

13

8

10

9