Okay. Are you sure it is all the wheels locking up? Let's try lifting the vehicle off all 4 wheels and try turning each one just to see if all of them are locked up. The only other common cause of this after someone works on it is the flexible brake line is twisted and not allowing the brake fluid to return so when you press the brakes, it pushes the fluid to the calipers but the line is restricted and doesn't allow it to return which holds the brakes applied.
Does that make sense?
As for the master cylinder, that is just the only thing that really makes sense for all 4 to be applied. Once it comes out of the master cylinder, you have individual lines and brake components so it is extremely unlikely for all 4 portions/legs of the system to be locked up the same way.
Friday, July 17th, 2020 AT 5:48 PM