- Mercedes-Benz approved hydraulic fluid or ATF oil. ATF = transmission fluid for automatic transmissions.
Examination
Check conditions:
- the car must be level (horizontal) surfaces);
- the engine must be turned off;
- the temperature of the oil in the hydraulic booster should be about +20°C.
1. Unscrew the cover 1 of the hydraulic booster reservoir 2 turns and remove it together with a measuring probe (see illustration).
2. Wipe the dipstick with a clean, lint-free cloth.
3. Inspect the O-ring on the power steering reservoir cap and make sure it is not damaged. Replace sealing ring if necessary.
4. Screw on the cover without tilting it.
5. Unscrew the cap again and check the fluid level. The hydraulic booster fluid level must be in the range indicated in the illustration by number 2. This range is indicated on the dipstick by the number «20°». A liquid is considered cold if its temperature does not exceed +20°C. When the liquid is hot, its level should be in the range 3 with the designation (+60°) (see illustration).
If necessary, add hydraulic fluid to the power steering reservoir. Do not agitate the hydraulic fluid before refueling as this will create air bubbles. Pour the liquid into the reservoir slowly, avoiding the formation of air bubbles. Be sure to fill in only fresh fluid, because even the slightest contamination can damage the hydraulic booster.
6. Screw on the cover without tilting it. Make sure the cover is screwed on correctly.
7. Start the engine and with the engine running, turn the steering wheel from side to side until it stops. This removes air from the power steering hydraulic drive.
If the fluid level in the hydraulic booster drops, you should contact the workshop to check its tightness and eliminate the leak. Replenishment of the volume of liquid will not lead to the desired result.