1. Locate the hydraulic fluid reservoir. It is usually located in the engine bay, near the power steering pump. On the SLK 230, it is located on the driver's side, near the windshield washer fluid reservoir.
2. Remove the cap from the reservoir. Be careful not to spill any fluid.
3. Use a funnel to add hydraulic fluid to the reservoir. The fluid level should be between the "MIN" and "MAX" marks on the dipstick.
4. Replace the cap on the reservoir.
5. Start the engine and let it run for a few minutes. This will circulate the fluid throughout the hydraulic system.
6. Check the fluid level again and add more fluid if necessary.
Tips:
* Use only the type of hydraulic fluid specified by the manufacturer.
* Do not overfill the reservoir. This can cause the pump to overheat and fail.
* If the fluid level is low, it is important to add fluid as soon as possible to prevent damage to the pump.
