17-32. TRANSMISSION OIL PRESSURE TESTS (3L80) (Cont' )
b. Control Valve and Governor Line Pressure Test
Remove pipe plug (3) from line pressure port (2) on left side of transmission (1).
Connect oil pressure gauge to line pressure port (2).
Direct all personnel to stand clear of vehicle before starting
engine. Transmission slipping into gear may cause injury.
This test must be performed with vehicle raised and tires off the ground.
Start engine (TM 9-2320-280-10) and check for leaks at connections.
Bring engine to operating temperature.
Hold modulator linkage in the full extended position during testing.
Activate kickdown switch manually or through the use of an electrical jumper lead. Apply service
brakes, place transmission shift lever in "D" (drive) and take foot off brake. Operate engine at 1,000
rpm and note pressure reading. Pressure should be 90-110 psi (621-758 kPa).
Slowly increase engine speed to 3,000 rpm and determine if line pressure drops below the reading
recorded in step 6.
If line pressure drops more than 10 psi (69 kPa), remove control valve and inspect for damage.
Replace control valve if damaged.
If line pressure drops less than 10 psi (69 kPa):
a. Remove governor and inspect for damage (para. 7-3), replace governor if damaged.
b. Check governor pipes, screen, and transmission case for obstructions to fluid flow. Replace
Remove oil pressure gauge from transmission (1) and install pipe plug (3) in line pressure port (2).
Remove electrical jumper lead from kick-down switch if attached.