Line Pressure Test: Measurement

NOTE: If the clutch or brake shows a sign of slippage, or shifting interval is not correct, check the line pressure.

Excessive shock during upshift 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 clutch, brake or control valve.

Set the vehicle on a lift.
Remove the under cover.
Remove the test plug and install the ST.
ST 498897200 OIL PRESSURE ADAPTER

Fig 1: Identifying Oil Pressure Adapter
Courtesy of SUBARU OF AMERICA, INC.
Set the ST1 and ST2.
ST1 498897200 OIL PRESSURE ADAPTER

ST2 498575400 OIL PRESSURE GAUGE
Lower the vehicle, and pull ST1 and ST2 into the vehicle.
ST1 498897200 OIL PRESSURE ADAPTER

ST2 498575400 OIL PRESSURE GAUGE
Connect the Subaru Select Monitor to the data link connector and read the current data. < Refer to READ CURRENT DATA , OPERATION, Subaru Select Monitor. >
Perform the line pressure test.

NOTE:

Do not perform the line pressure test for more than 5 seconds at a time. Doing so will make the engine oil and ATF deteriorate and the clutch and brake to be adversely affected.
After performing the line pressure test, be sure to cool down the engine for at least one minute with the select lever set in "P" or "N" range and with the idle speed at 1,200 RPM or less.
Adjust the throttle valve angle in order to match the "P/L Solenoid Pressure" displayed on the Subaru Select Monitor.

THROTTLE OPENING ANGLE CHART

Range of the selector lever	Throttle opening angle	ATF temperature condition	"P/L Solenoid Pressure" displayed on the Subaru Select Monitor kPa	Standard line pressure kPa (kg/cm^2, psi)
D	Full closed	45 - 55°C (104- 131°F)	490	385 - 555 (3.93 - 5.66,55.8 - 80.5)
D	Full open		1,370	1,235 - 1,475 (12.59-15.04, 179.1 -213.9)
R	Full closed		1,370	1,530-1,925 (15.60 - 19.6, 221.9 - 279.2)