See also:

Checking the Brake Fluid Level
WARNING: Use caution when handling brake fluid. It can damage your vision if it gets into your eyes. It will also damage your vehicle's paint if spilled on it and not removed immediately. ...

Brake/clutch fluid
Check brake fluid level in the brake fluid reservoir. The level should be between “MIN” and “MAX” marks on the side of the reservoir. Use only hydraulic brake fluid conforming to DOT 3 or DOT 4 sp ...

Valve clearance
Inspect excessive valve noise and/or engine vibration and adjust if necessary. An authorized HYUNDAI dealer should perform the operation. ...