I have an 02 Grand Caravan, a couple of weeks ago on a trip the van started to shake like a piece of rubber had come off of a tire, we stopped and the left rear caliper was smoking, we got it to a Dodge dealer where they replaced both rear capilers and pads and he said the right rear was the problem, after that it worked ok until the other day when the left front started to lock up same shaking as before to the point of being violent, I replaced both front calipers and pads and could not get a firm pedal after that, I then replaced all the brake hoses and the master cylinder, still feels like it has air in the system. I have bled it numerous times and it is still not right. The van has ABS, 4 wheel Disc and traction control. The master cylinder does not appear to be leaking and after 3 pumps the pedal feels fine and it will stop good. There are no warnings being displayed on the dash.
Ideas???? I have worked on vehicles for years and never had anything like this.