Next time they lock up, loosen the steel lines at the master cylinder. If that lets them release, the brake fluid was contaminated with a petroleum product. That will be a very expensive repair. If that appears to be the cause, get the brakes to lock up again, then loosen the mounting nuts for the master cylinder and pull it forward from the power booster 1/8". If THAT lets them release, check the adjustment of the brake light switch or for something else holding the brake pedal down a little.
If loosening the lines at the master cylinder doesn't help, loosen them at the ABS hydraulic controller. If that is what's holding the brake fluid under pressure, replace the controller.
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Thursday, February 28th, 2013 AT 10:17 PM