I was replacing my sister's brake pads today and I noticed that the right side pads were completely worn but the left had a good deal left in them. What could have caused this. When I put the new rotors and pads on the both tires have considerable drag in them like the brakes are applied. What should I check or replace.

 

First, what car and what kind of caliper style? Floating, sliding? or fixed?(probably not) Second, make sure it has the right lubricant. use SILICONE ONLY! Last but not lease, make sure the piston is not seized up. Give me more info on this I can help you out.

 

Sounds like a stuck piston in the caliper.