hi guys .i have a 95 neon with all wheel disc brakes.2 months ago when i returned from a long drive to and from philly i developed a scraping noise..checked it out and the right rear rotor was scored,the pads were shot(the pad closest to the caliper piston was bent and down to the metal,the other pad was in better shape)the caliper piston tip was broken up and pwdery....this was all on the passenger side rear.the other side ws fine.....i changed the caliper,pads and rear rotors to new.now the car worked fine but the right rear tire was still dragging.2 months of in town driving and was still ok.....took another trip to philly and when i got back i had the same problem.new caliper piston was broken up at tip,pads shot and rotor corn.....if its not the caliper........THEN WHAT IS IT??PLEASE HELP

 

Did you replace the slides for the caliper? The bolts?

When you say right rear rotor, do you mean driver side (which is what most people call the right rear) or passenger side, which is the true right rear?

Did you take a look at your parking brake? Parking brakes are the most common cause of rear brake drag.

 

passenger side rear..and yes i checked the parking brakes and the parking brakes on that side dont grab the rotor when applied so thats obviously not it...also the pins or caliper bolts are new and i did put white silicone grease on them.im ruling out the proportioning valve(wherever the heck that is)because the other 3 wheels work fine.i followed the brake line and there are no kinks in it.is it possible that the master cylinder could be causing this?

 

The proportioning valve is part of the master cylinder.

Are there two separate lines running to the rear? Or just one with a Tee?

 

2 separate lines running to each side

 

Could be the valve on the master cylinder then. I'm not sure why it would only act up on long trips though [&:]

 

i dont think it is acting up on the long trips only but the damage is probably done during them because of the massive heat build up from the dragging for such long periods at a time..that is 3 hours and 150 miles each way of the pads dragging on the rotor..after the ride i could smell burning and the rotor was so hot it was rainbow colored and black.now that is some magor heat buildup.ok so is that valve(i assume your talking about the proportioning valve)replaceable or do i have to replace the master cylinder as a unit?

 

just bumpimg this thread to get a response

 

b

 

Ok, Duplicate the concern so the wheel is locked, hopefully your lines are not to rusted, and crack the hose going into the rubber hose and see if the brakes release, if it does not then crack the bleeder, at that time does the caliper release, if it does your rubber hose is acting like a one way valve allowing you to put pressure on the caliper but the pressure wont release. Remember you should rebleed your brakes after doing this. If it does release when cracking the line before the rubber hose, Then bleed the brakes duplicate the concern and start at the master working your way to that wheel, the point where it releases and the previous point that it did not release is your problem. Ive seen a few hose cause this, just my .02