Brake issue, possible frozen piston/caliper?
I have a 2002 Toyota Solara 2.4L 4-cylinder with 198,000 miles with a weird issue. About a year ago, my car started shaking after driving it on the highway for more than 2-3 minutes. This is my daily driver, and my daily drive is less than 10 miles, all on surface streets, so I rarely notice the problem.
Now it's getting worse - shaking the steering wheel, the whole car vibrates, and stuttering/surging braking coming off the highway from highway speeds to a full stop. Even after a stop, it continues shaking until it has a chance to sit for 10 minutes or longer. It's definitely seems like a brake issue, possibly a warped rotor, but only when I've been driving on the highway.
The rotors only have maybe 15,000 miles on them. I upgraded to drilled and slotted rotors about 5 years ago. I hate replacing them already, but what are you gonna do? So I pulled the wheels off, and the rotors are still too hot to handle, so I tried a little test. The car is securely up on jackstands. I started it and put it in drive to see if I could see which rotor was warped. Only the passenger rotor spins. The drivers side rotor is locked up - I can barely spin it with a wrench.
So my question is, do I have a stuck piston or caliper? If so, what causes that and how is it fixed? Or if the caliper is fine, do I simply have a warped rotor, or is there more going on? I'm assuming I'll need new rotors regardless.