Hydraulic System Pressure Test

NOTE: Before testing, fluid temperature should be at least 176°F (80°C).

Disconnect pressure lines from steering gear and pump. Install Pressure Gauge (09631-22020 ) with gauge side connected to pump and valve side of gauge connected to pressure line. See Fig 1.

Fig 1: Installing Pressure Gauge
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Bleed air from system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. Ensure fluid level is correct. Start engine, and allow it to idle. Close valve and note pressure reading. Open valve.
CAUTION: DO NOT close valve longer than 10 seconds.
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 readings 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 power 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 power steering, turn wheels to full lock position. Disconnect electrical connector from solenoid valve located on steering gear. See Fig 2.

Fig 2: Connecting Wiring to Solenoid Valve (P/U W/ Electronic P/S)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 longer than 30 seconds. Allow solenoid valve to cool between test procedures.
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 and ground to solenoid connector terminals.
Solenoid valve needle should be drawn into solenoid valve approximately .79" (20.0 mm). Replace solenoid valve if needle does not operate as specified.
Reconnect electrical connector at solenoid valve and note pressure reading. Pressure should be at least 1067 psi (75 kg/cm² ). If pressure is low, check electronic power steering system. Refer to the STEERING SYSTEM - ELECTRONIC POWER article in the STEERING Section.