i have a '96 geo prizm.281,000 mi.and the brakes apply by themselves at random times.i’m lost as to why and when they do they stay applied so hard that the car will no move at all.when this happens i have to wait until the car cools off before i can drive again.if i wail 30 min.or so the car is fine and it doesn’t happen again for quit awhile.if anybody has any idea why this happens PLEASE help.

You ma have a clogged break line or claiper sticking.
When it does it you must lift wheels and see if 1 or all wheels are stuck then you can go from there.

My best guess is that one or more of your flexible brake lines are swelling internally, and are not allowing brake pressure to be released from one or more wheels.

I think we need to narrow down the “random times”. How many miles into a trip? Weather? Freeway/city? Load? etc. and do you normally set the parking brake?

well brake lines have all been checked and calipers changed

that’s just’a very set miles,i live in the weather is mostly happens on freeway and load just my big rear{230 lb.}and no i don’t use the parking brake it’s an automatic.and flat random i ment it can go weeks and not happen,then it can do it every day for a i said…random

You need to do as advised,when the problem does occur jack the car up and find out how many wheels are locked. Plese give a report of all work performed from the start.