I recently replaced my brake booster and rear calipers, pads and flex hose to the calipers. Truck brakes fine for a few miles then rear drivers side brakes lock up. When I shut truck off and let it sit for a few minutes then start it back up , the brakes release and work fine for another few miles. I've sunk alot of money into this problem and still no fix. What could it be?

99 chevy Blazer 2dr, with all four disk brakes. no drum brakes.

 

Did you check the slide pins to see if theyre frozen. Also may be the caliper itself. I believe the piston in the caliper is made of plastic and can become warped but i would start with the slide pins first and make sure theyre lubed up good with caliper grease and sliding smoothly.

 

I'm really sorry the hoses didnt fix it.
But you should have used the same thread to report this.

Here's a thread that may touch on some of your problems.
https://blazerforum.com/forum/2nd-ge...es-4447/page2/
I'm also wondering about if the parking brake may have something to do with it.

 

It's not the sliding pins or the piston. both are new and pins are lubed and sliding. Only after the breaks build up pressure they lock up but after cutting off the car and waiting, the caliper releases. It cant be the parking break because its only the right rear tire. doesn't the parking break stop all tires? I'm not sure

 

Depending on how the equalizer is rigged, if there was something flukey causing the cable to flex on suspension travel it could advance the parking cam. I think it's a long shot but might be interesting to disconnect the cable at the caliper and see if it still did it.

Also did you have any trouble getting the piston to retract some when you rechecked the caliper?

 

Sounds like a flex hose.
I see you changed them but did you only change the 2 that attach to the calipers?
I think there is a third flex hose between the line coming down the frame rail and the spliter tee going to the calipers.

 

If that hose was bad wouldnt it cause both rear calipers to seize up and not just the drivers side? Could a bad master cylinder be the cause of the problem? If not someone told me that sometimes Advance Auto Parts (where I got the caliper from) sometimes use rebuilt parts and that the caliper could be faulty. It's under warranty so I could replace it.

 

No, the piston and sliding pins seem to be working fine, no trouble getting them to retract. about the parking brake, ur saying I should disconnect the parking brake from that tire?

 

It seems like all of my tires are locking up. Im not 100% sure the front tires are but I am 100% both rear tires are locking up. I disconnected the parking brake so thats out of the equation.I replaced both brake caliper flex hoses. Still no fix.

 

i had my proportioning valve get stuck in a certain position (dont remember what position it was) and i had no back brakes at all. so if its only your back brakes locking up could it be your proportioning valve getting stuck in the opposite position that mine did? if your front tires are also locking up i would start looking at the master cylinder.