Replacement materials:
Transmission oil (ATF), For example:
- Shell ATF Dexron IID-21 -631
- Mobil ATF 220 D-20104
- Total Dexron IID-2129B
For approval of other transmission fluids, contact your BMW representative.
The oil level can be checked both cold and at operating temperature. The operating temperature of the oil is approximately +80°C, when cold, the oil temperature is equal to the ambient temperature.
With the engine off, unscrew the reservoir cap. Wipe the level indicator on the cover with a clean, lint-free cloth.
Insert the level indicator on the lid into the tank and, without wrapping the lid, remove it again. The oil level should be between the marks on the indicator. Adjust oil level if necessary. The level should only be topped up with automatic transmission oil (ATF) with marking Dexron II approved by BMW (the corresponding inscription must be on the packaging). Be sure to add only new fluid, as even the slightest contamination can lead to a malfunction of the hydraulic system.
Start the engine and, if necessary, add oil until the level is between the marks.
After that, with the engine running, turn the steering wheel to the right and left several times until it stops, due to which air is bled from the hydraulic drive.
Stop the engine. In this case, the oil level in the tank can rise 5 mm above the MAX mark. Check the sealing gasket of the reservoir lid for porosity and damage.
Close compensation tank.