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. Following manufacturer's instructions, install Pressure Gauge (09631-22020 ). See Fig 1.
- Bleed air from system. See HYDRAULIC SYSTEM BLEEDING under LUBRICATION. Ensure fluid level is correct. Start and idle engine. Close valve and note pressure. Open valve.CAUTION: DO NOT keep valve closed longer than 10 seconds.
- Compare pump pressure reading to specification. See POWER STEERING PUMP PRESSURE TEST SPECIFICATIONS . Replace power steering pump if pressure is less than specified.POWER STEERING PUMP PRESSURE TEST SPECS
Application psi (kg/cm2 ) 3.0L (3VZ-E) 1140 (80) - With valve open, record pressure with engine speed at 1000 and 3000 RPM. Difference between readings should not exceed 71 psi (5.0 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. See POWER STEERING PUMP PRESSURE TEST SPECIFICATIONS . If pressure is less than specified, steering gear has internal leak and must be repaired.
- On Pickup with electronic power steering, turn wheels to full lock position. Unplug electrical connector from solenoid valve, located on steering gear. See Fig 2.
- With valve open and engine speed at 1000 RPM, note pressure. See POWER STEERING PUMP PRESSURE TEST SPECIFICATIONS . If pressure is less than specified, steering gear has internal leak and must be repaired.
- Connect battery voltage to solenoid valve electrical connector. See Fig 2. Note pressure reading. Maximum pressure should be 570 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, measure 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 0.8" (20 mm). Replace solenoid valve if solenoid does not operate as specified.
- Reconnect wiring harness to solenoid valve. Note pressure. See POWER STEERING PUMP PRESSURE TEST SPECIFICATIONS . If pressure is less than specified, check electronic power steering system. See STEERING SYSTEM - POWER RECIRCULATING BALL article in this section.