New Brake Lining is required to be Conditioned before release the aircraft for flying.
Brake lining conditioning procedure as per Cessna 172R MM
A. Non-asbestos organic lining:
(1) Taxi airplane for 1500 feet (457.2 m) with engine at 1700 RPM, applying brake pedal force as needed to develop a 5 to 9 knots (9.3 to 16.7 km/hr) taxi speed.
(2) Allow brakes to cool for 10 to 15 minutes.
(3) Apply brakes and check to see if a high throttle static run up may be held with normal pedal force. If so, burn-in is completed.
(4) If static run up cannot be held, allow brakes to completely cool then repeat steps 1 through 3 as needed to successfully hold.
B. Iron-based metallic lining:
(1) Perform two consecutive full stop braking applications from 30 to 35 knots (55.6 to 64.8 km/hr). Do not allow the brake discs to cool substantially between stops.
NOTE: Light brake usage can cause the glaze to wear off, resulting in reduced brake performance. In such cases, the lining may be conditioned again following the instructions set forth in this conditioning procedure.