The oil level must be checked when the engine is cold or warm (not higher than +50°C).
Warning: Do not hold the steering wheel fully turned in either direction for more than five seconds. This may damage the steering pump.
The power steering system reservoir is located in the engine compartment and has a screw-on cap with a measuring probe built into it.
1. Park the car on a level surface and apply the parking brake. Set the front wheels to the "straight ahead" position.
2. Unscrew the oil reservoir cap. Wipe the level indicator on the cap with a clean, unruffled rag.
3. Screw the cap back on and unscrew it again by hand. The oil level should be 2 mm above or below the MIN mark.
4. Be sure to add only clean oil to the system, as even minor contamination can lead to malfunctions in the hydraulic system.
5. Screw the tank cap on by hand.
Checking at engine operating temperature
1. Warm up the engine and stop it. The oil should warm up to a temperature of + 50°C.
2. Let the engine idle and set the wheels straight.
3. Check the oil level with the engine running. The oil level with the plug screwed in should be between the MIN and MAX marks.
(Information obtained from this resource: AUDIMANUAL.ru)