On the older a/c using Master cylinder (light a/c) pressure is a direct function of the force applied using our foot. With air trap in the line it may well expand with temperature especially during brake application. This energy would then be absorb by the brake fluid and subsequently by the trap air. Because the brake system is a close loop, the heat absorb by the air may well cause it to expand and increase the fluid press within the close loop causing the caliper to perhaps lightly grip on the wheel rotor when foot pressure has been remove. This grip may be to light to be felt in the cockpit but may well be sufficient to generate heat during the taxi roll to bay after landing preventing the heat from the landing to be decipated in the normal rate resulting in hotter brake.
Well...er....how did I do?