I have 1998 Chevy Tahoe 4WD. I have changed my callipers, front brake lines, master cylinder, new brake shoes. When I am driving for about 15min .My brake pedal gets so hard that I cant press it and my vehicle gets stuck and won%26#039;t move at all. I have to wait until the brakes cool down for about and hour and then I am able to move the vehicle again. And it just repeat itself.|||Wow thats not good, before I read all of the question I was thinking it was your Booster because it is supposed to make pushing the brake easier by using vacuum pressure. But as I read on you mentioned it stuck, Thats not good at all bud. Sounds to me like your pads may be on loose or something of that sort wasn%26#039;t hooked up right. I%26#039;m not an expert but you better get that looked at as soon as you can before something bad happens.|||That is a strange one. I know GM has a brake sensor system that your lines run through. A box under the hood near the master cylinder.
I%26#039;ve heard of that going bad. I%26#039;m not sure if it would cause your problem. Try bleeding the brakes at the master cylinder to see if that helps. You may have air in the line. Normaly you wouldn%26#039;t think air would cause them to stop the vehicle.
I had that happen on a Honda and it was a vaccum problem. Some sort of vaccum box was the problem.|||I don%26#039;t think it%26#039;s ABS. The only things you haven%26#039;t replaced is the vacuum booster and proportioning valve. If you can get them to lock, jack up the car and check to see which whells won%26#039;t turn (make sure parking brake is disengaged and trans is in neutral to check the rear). This should tell you which wheel(s) are locking and may aid in troubleshooting.
