if it is just one wheel locking up, check the brake hose, caliper for seizing or the slide pins for holding on brakes.

roy

thanks roy.got another question before i spend anymore money.give you some history.first i had front rubber hoses replaced&rear drums swapped to disc.it had low brake pressure,car would take a while to stop,but no locking issues.then i had the prop valve rebuilt.this is when locking problems started.also when front brakes lock up i have to let them cool off for an hour before pedal loosens up &i can drive again for about 10mins.front brakes smoke bad too.was thinking prop valve? since this is a dealership part,could i use adj prop valve off the internet?i've gotten mix reviews saying they dont work only use oem parts.dont know where you can get oem prop valve.again thanks.