Hydraulic System Pressure Test

NOTE: Fluid temperature should be at least 176°F (80°C) before testing.

Disconnect pressure lines from steering gear and pump. Install Pressure Gauge (SST 09631-22020 ) with gauge side connected to pump and valve side of gauge to pressure line. See Fig 1.
Bleed air from system. See appropriate HYDRAULIC SYSTEM BLEEDING in this article. Ensure fluid level is correct. Start engine and allow to idle. Close valve and note pressure reading. Open valve.
CAUTION: DO NOT close valve for more than 10 seconds.

Fig 1: Installing Pressure Gauge
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Pressure should be at least 1067 psi (75 kg/cm² ). Replace power steering pump if pressure is low.
With valve open, record pressure with engine speed at 1000 and 3000 RPM. Difference between both reading should not exceed 71 psi (4.9 kg/cm² ). Replace flow control valve in power steering pump if difference exceeds specification.
On all models except Pickup with electronic steering, turn wheels against lock and note pressure reading with valve open. Pressure should be at least 1067 psi (75 kg/cm² ). If pressure is low, steering gear has internal leakage and must be repaired.
On Pickup with electronic steering, turn wheels to full lock position. Disconnect electrical connector from solenoid valve located on steering gear. See Fig 2.
With valve open and engine speed at 1000 RPM, note pressure reading. Pressure should be at least 1067 psi (75 kg/cm² ). If pressure is low, steering gear has internal leakage or solenoid valve is defective.
Connect battery voltage to solenoid valve electrical connector. See Fig 2. Note pressure reading. Maximum pressure should be 569 psi (40 kg/cm² ).
CAUTION: DO NOT connect voltage to solenoid valve for more than 30 seconds. Allow solenoid valve to cool between test procedure.
If pressure is high, check resistance between solenoid terminals. Replace solenoid if resistance is not 6-11 ohms. If resistance is okay, connect battery voltage to solenoid connector terminals.
Solenoid valve needle should be drawn into solenoid valve approximately .79" (20.0 mm). Replace solenoid valve if needle did not operate as indicated.
Reconnect electrical connection at solenoid valve and note pressure reading. Pressure should be at least 1067 psi (75 kg/cm² ). If pressure is low, check power steering system. See STEERING SYSTEM - ELECTRONIC article.

Fig 2: Connecting Wiring to Solenoid Valve