Air enters the hydraulic system when the system is depressurized during repairs, replacement of individual components or fluids.
When bleeding the power steering hydraulic system, proceed as follows:
Set the front wheels to drive straight ahead.
Check and, if necessary, top up the fluid level in the power steering reservoir to the Cold mark on the level gauge.
Start the engine and let it run at idle speed.
Recheck and, if necessary, bring the fluid level in the power steering reservoir to the Cold mark on the level indicator.
Rotate the front wheels from side to side without stopping to bleed air from the power steering hydraulics. Constantly monitor the fluid level in the tank.
After bleeding the hydraulic drive, set the front wheels to straight ahead and run the engine for a few minutes.
Recheck the fluid level in the power steering reservoir, which should be near the Hot mark on the level gauge.