So my brakes when I first start my car go really far to the floor and are soft, but after 10 15mins of driving they get supper hard and the brakes Lock up!!!!! Any idea what needs changed or fixed? Thanks everyone
Is the peddle spongy at fist or just go to the floor? If spongy then you have air in the lines and need to bleed the brakes.
Is this new? Have you done any work on any part of the brake system?
Cheapest is to bleed the brakes and make absolutely sure there is no air in the lines. Air in the lines will lead to peddle to the floor when cold but as the lines heat up the air will expand and may cause the lock up.
I don't think there is a vacuum leak because you didn't say the brakes were hard to apply. Same with a brake booster issue.
Correction, cheapest would be to check that the master cylinder isn't leaking. just put a bunch of paper towels around the cylinder and see if you get any fluid on them.