2009 Equinox FWD has a unique brake issue. I had the master cylinder and alternator replaced after a brake issue where there would be no brake pressure and was unable to stop the vehicle. Post repair the brakes work normally but over time get stiffer and stiffer until they lock up. If I turn the engine off and then restart the issue resolves but will happen again later with the same solution resolving the issue temporarily. I returned the vehicle to the mechanic, who sent me to the dealership and both places said "No problem to be found." I will add that periodically the traction control light will come on but will turn off by the next time I drive. I'm honestly at a loss, and would like to get this resolved without throwing money at the problem with nothing getting resolved.

 

do they unlock if you unplug the booster?