PDA

View Full Version : Dragging brakes


My5ABaby
04-27-2009, 09:30 AM
Is it normal to hear the front pads dragging while the front end is in the air?

Also, what would cause the pistons in both of my back brakes to not retract fully and drag?

vex
04-27-2009, 10:02 AM
Is it normal to hear the front pads dragging while the front end is in the air?
Depends. It's not going to behave as though it doesn't have brakes on it. It will drag a little bit, but should be very easy to move by hand. The drag coefficient of the brakes are not big enough to slow the car while moving.
Also, what would cause the pistons in both of my back brakes to not retract fully and drag?
That would probably be the "ratcheting" ability of the rear brakes. As the rear pads get lower, the parking brake incrementally adds additional pressure (not really pressure, but height to the piston) to allow the emergency break to function properly.

In other words if you can turn the wheels by hand, you're fine. If they're dragging more than that you're not fine.

My5ABaby
04-27-2009, 10:56 AM
The left right might not be that bad, but it didn't spin that well when in the air. However, the right rear was heating up the rotor substantially while driving.

vex
04-27-2009, 11:01 AM
The left right might not be that bad, but it didn't spin that well when in the air. However, the right rear was heating up the rotor substantially while driving.

Then something is wrong with the caliper to the proportioning valve. Check to make sure you have even wear on the rear pad, maybe even double check the caliper for proper action. Remember you'll have to screw-in/rotate the piston to have it retract. Also double check to make sure you have all the springs installed, etc.

I'm just guessing but what may have happened is that the spring got lost some where and when you pulled the e-brake the brakes were never reset by the force of the spring. Just a thought and probably not what actually happened.

My5ABaby
04-27-2009, 11:18 AM
Springs are there. I manually retracted the piston and it didn't drag, but after hitting the brakes once it started dragging again.

vex
04-27-2009, 11:35 AM
Springs are there. I manually retracted the piston and it didn't drag, but after hitting the brakes once it started dragging again.

Then it's definitely applying too much pressure and retaining that pressure. Try bleeding out your brakes, if that doesn't work you may need to rebuild that caliper.

My5ABaby
04-27-2009, 12:05 PM
I've bled them a couple times so that shouldn't be a problem. I'm getting replacement calipers/rotors (since they're currently 23 years old) so hopefully that will help. Thanks for the help.

vex
04-27-2009, 12:26 PM
Hope it is your caliper. If you're still having problems start checking your proportioning valves.

My5ABaby
04-27-2009, 12:30 PM
Hope it is your caliper. If you're still having problems start checking your proportioning valves.

When I figure out what that is, I'll check it. :001_005:

vex
04-27-2009, 12:41 PM
http://www.rotorwiki.com/images/6/6c/11_braking.pdf
25/67 gives you info on how to check it and what it is.

Shadow24v
04-27-2009, 10:48 PM
not to hi-jack but my FC has a similar issue, it doesn't seem to affect driving at the moment, but the fronts are hard to turn by hand when its jacked up. thats AFTER a 600 mile trip on a tow dolly (rear end on the dolly, fronts rolling). I might be looking into remaned calipers if it doesn't clear up