Line Pressure Test - Subaru IMPREZA 2002 Service Manual

LINE PRESSURE TEST
I
AUTOMATIC TRANSMISSION
7.
Line Pressure Test
A: MEASUREMENT
1.
GENERAL INFORMATION
If the clutch or the brake shows a sign of slippage or
shifting sensation is not correct, the line pressure
should be checked.
Excessive shocks during upshifting or shifting
takes place at a higher point than under normal cir-
cumstances, may be due to the line pressure being
too high.
Slippage or inability to operate the vehicle may,
in most cases, be due to loss of oil pressure for the
operation of the clutch, brake or control valve.
1) Line pressure measurement (under no load):
CAUTION:
Before measuring line pressure, jack-up all
wheels.
Maintain temperature of ATF at approximate-
ly 50°C (1 22°F) during measurement.
(ATF will reach the above temperature after
idling the engine for approximately 30 minutes
with select lever in "N" or "P".)
2) Line pressure measurement (under heavy load):
CAUTION:
Before measuring line pressure, apply both
foot and parking brakes with all wheels
chocked (Same as for "stall" test conditions).
Measure the line pressure when the select le-
ver is in "R", "2" with engine under stall condi-
tions.
Measure the line pressure within 5 the sec-
onds after shifting the select lever to each posi-
tion. (If the line pressure needs to be measured
again, allow the engine to idle and then stop.
Wait for at least one minute before measure-
ment.)
Maintain the temperature of ATF at approxi-
mately 50°C (1 22°F) during measurement. (ATF
will reach the above temperature after idling the
engine for approximately 30 minutes with the
select lever in "N" or "P".)
2.
TEST METHODS
1) Temporarily attach the ST to a suitable place in
the driver's compartment, remove the blind plug lo-
cated in front of the toe board and pass the hose of
the ST to the engine compartment.
ST 498575400 OIL PRESSURE GAUGE
ASSY
(A) Pressure gauge hose
(B) Hole in toe board (blind plug hole)
(C) Brake pedal
2) Remove the test plug and install the ST instead.
ST 498897200 OIL PRESSURE GAUGE
ADAPTER
(A) Test plug
3) Connect ST1 with ST2.
ST1 498897200 OIL PRESSURE GAUGE
ADAPTER
ST2 498575400 OIL PRESSURE GAUGE
ASSY
AT-1 6