That isn't good. Power steering fluid will cause a lot of damage, quickly. Power steering fluid will cause seals to immediately begin swelling. As the seals swell, they expand and block passages causing issues such as you described. In this case, I feel the return ports in the brake master-cylinder are blocked and preventing the brakes to not release. Also, braking produces heat and the fluid to expand. If the fluid can't return to the reservoir when you release the pedal, due to swollen seals, the brakes remain applied, creating more heat and expansion, and eventually the brakes lock up. Usually, that will happen within a short distance.
The only truly effective way to fix the problem is to take everything apart and replace every rubber part and flushing out the others. Now, since some parts were already replaced, chances are they are now contaminated as well.
I wish I had a better answer, but I feel this is what has happened.
Let me know if you have other questions.
Friday, May 15th, 2020 AT 9:32 PM