I have a 2007 hyundai elantra that I just bought a month ago and it’s starting to have problems with the brakes. After ten to fifteen minutes of driving, the brake pedal starts to get really hard and the gear shifter won’t switch gears, I have to use the shift lock release slot. The first time it happened, I was driving 60 mph then the brake pedal acted as described and the front brakes started to smoke. After the brakes locked up, the car quickly dropped down to about 30 mph and the car started to shake and jerk. Also, when I went to park, the car wouldn’t idle and the gear shifter was stuck. I am by no means car savvy person, so I took it to my roommate who works on cars and he thought that it could’ve been the brake calipers. We went to to autozone to buy new ones so he could replace them, but the same thing has continued to happen. Later on I had my dad drive the car so he could get a better understanding of what was happening to my car and at first the car drives great with no problems. The gear shifter works fine, brake pedal is as should be, the car idles, everything is fine, but after a few minutes of driving, it gets stuck. I’ve noticed that the brakes don’t seem to smoke up as fast unless I drive about 50 or 60 mph for a minute or two. I would really appreciate any feedback.