Removal of air from system of the hydraulic booster
Check the tightness of the hydraulic fittings. With the engine off, top up hydraulic fluid in power steering fluid reservoir up to the mark "MAX" (cold). Lift the front of the car and quickly turn the steering wheel from side to side (but not all the way) as long as the liquid level in the tank is no longer changed. Start up the engine and repeat the operation for some time when the engine speed to idle. Bring the liquid level to normal.