TM-9-2350-311-20-1

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

TECHNICAL MANUAL; UNIT MAINTENANCE MANUAL FOR HULL, POWERPLANT, DRIVE CONTROLS, TRACKS, SUSPENSION, AND ASSOCIATED COMPONENTS

AUGUST 1994

TM-9-2350-311-20-1 - Page 859 of 1275

9-3 PRESSURE CHECKS — CONTINUED

Pressure Checks — Continued

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Remove pipe plug from test point to be pressure tested.

Install pressure gage tester.

Start engine.

Shift transmission to desired range (Table 9-1).

Slowly increase engine speed to desired rpm (Table 9-1).

NOTE

When making steer clutch pressure tests, move steering bar slowly from horizontal

to full steer in desired direction while watching pressure gage. Note pressure rise

to maximum as steering bar moves to full steer.

When making lockup engagement tests, increase engine speed slowly until lockup

apply pressure is indicated on pressure gage. Record pressure and engine speed.

Record governor pressure at lockup engagement.

When making lockup release tests, first increase engine speed higher than lockup

engagement speed, then slowly reduce engine speed while watching pressure

gage. When pressure drops quickly, record governor pressure and engine speed.

Record readings for each test point.

9-4

TM9-2350-311-20-1