Horrible experience yesterday has left me completely confused. I stupidly accelerated very fast and hit the brakes very hard in a short amount of time. About a half hour later, driving around, the car had a wobbling feeling and I noticed a smell. I drove it right to the first firestone I could find, went to lunch, came back and car was still sitting in same front parking spot. I went in and they showed me an estimate of work that needed to be done. Said front left caliper was frozen, front brake pads, front rotors, and fluid need to be replaced. Total bill 900 dollars with my military veteran discount. Back breaks were replaced in 9/2017 and front brakes 2013. My gf insisted we go and they gave us a really hard time not letting us leave saying it was unsafe. She drove it another 20 minutes without any problems to our local firestone that did my inspection a few months ago. This shop looked at it and said there was nothing wrong and to take it back if it happened again and ask to drive it with a tech. Car is 2009 Hyundai Sonata and can't afford to lose it. Any ideas on problem? Get a third opinion? Thanks in advance.
If the caliper really was frozen/blocked/sticking, that could've made your brake keep being applied while you where driving. You should've noticed that in weak acceleration and sharp deceleration. The brake being applied will get the brakepad heat up quickly to the point of you smelling it, which you mentioned. If pads get too hot, the glue holding the liner can liquidise into the pad, creating glazed pads. Pads in that condition will perform very poor. If brake discs get too hot, they can warp, causing a vibration in your steer when braking. If everything gets way too hot, your caliper can get some damage, but that doesn't happen very quickly.
If the scent you mentioned was smelling like something was being burned, and your 'wobbly' experience is like i described, then you do have warped discs and pads that may be in poor condition. In that case, i'd advise you to replace the pads to keep being ensured of good braking performance, and i'd recommend to replace the discs because warped discs cause an annoying driving behaviour. The caliper(s) should be replaced if inspection turns them out to be damaged.
You can keep using the old discs if you can live with it, but i would advice against it. It's really annoying to have your steer vibrate everytime you brake, and discs often don't cost too much. For $900 i'd expect all my discs, calipers, and pads being replaced. Else it's way too expensive.