I agree with others you need to change the way you go down hill. Get new rotors (try to stay away from made in china).
Then use the "Aggressive Braking Method" for going down hill. Start at the top in a lower gear. Let the rig get to a decided upon speed (I used 45MPH in 2nd gear). Brake hard and slow down 5 to 10 MPH, release the brakes and let the speed build up again to your decided upon speed. Brake hard, slow down 5 to 10 MPH and release keep doing this until you get to the bottom of the hill. This allows the brakes to cool a little in between braking.
I've gone all the way down to 1st gear on 10% grades to keep from overheating brakes. In 1st gear I use 25MPH as my max speed.
You're not driving a sports car so you have to use the engine braking to save the brakes. Just don't over rev the engine...