number 1,
change your driving style when driving in the moutains, the basic problem is that your pads become heated and the brake pad surface nearest to the rotor becomes a liquid mess and when u need the brakes they have overheated and will not stop because the frictional forces needed to stop the car are not there.
apart from the driving issue, use ONLY genuine brake pads. and get your brake system flushed and brake lines bled. also take care about what kind of brake fluid you use, only use the recommended DOT fluid for your car.