See also:

Breaking-in of new brake pads and linings
When replacing the brake pad or lining, use only genuine SUBARU parts. After replacement, the new parts must be broken in as follows. ...

If steam is coming from the engine compartment
Turn off the engine and get everyone away from the vehicle until it cools down. ...

Brake pad and lining
While maintaining a speed of 30 to 40 mph (50 to 65 km/h), step on the brake pedal lightly. Repeat this five or more times. ...