2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Are my brakes dragging?...

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Old Jun 24, 2006 | 10:23 PM
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From: Japanabama
Are my brakes dragging?...

Ok, after adjusting my pedal height (which was a bit high I think), I've been trying to get the pedal to feel like it did before (which was very stiff), and ended up making the brakes drag but adjusting it too much... I didn't notice they were dragging until I drove around and when I got home I realized car wouldn't roll... lol.

I adjusted it again, and after driving around for about 2 minutes, they got pretty damn warm again, although when I jacked it up, the wheels turned fairly freely, although maybe just a bit less freely than before. Or maybe that was only the normal operating temperature, although I kind of doubt it...

What I want to know is, should you hear the sound of the pads rubbing lightly on the rotors (a slight "hiss" sound) even though the wheel is turning freely? Or should there be no noise at all?

If there should be no noise at all, I think my brakes might have been dragging the whole time, since it always had SOME pad hissing when it free-rolled (maybe that explains the 15 MPG? :p)

The car still stops just fine, even when adjusted to have more free-play than it does now, although the way that it has a bit more give before it stiffens up kind of annows me (it used to have a more stiff feel, even with the engine on). I think maybe this is because it has less leverage since I lowered the pedal height. It's really just me being picky about pedal feel...

The last thing I need is less leg room though!
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Old Jun 25, 2006 | 12:02 AM
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From: Shifting into third
Maybe it isn't the pedal height.

Maybe a caliper is seized.

There shouldn't really be any noise.

Did you check the pads for uneven wear?
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Old Jun 25, 2006 | 12:46 AM
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From: Japanabama
The noise is basically just the sound of the pads rubbing very lightly against the rotors... Also, the pedal play seems fine to me, so I wonder what could be wrong with it...

Maybe there is supposed to be a bit of slack before it gets tight instead of just being stiff?...

Of course, I might also have a vacuum issue, since when I press on the brake the idle drops just a tiny bit.
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Old Jun 25, 2006 | 01:56 AM
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From: New York
You should hear a slight noise of pad against rotor when free turning it with the wheel on.

It shouldn't be difficult to turn, but shouldn't spin indefinitely either.

Maybe 2-3 turns on a one handed spin. Nassayin?
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Old Jun 25, 2006 | 02:39 AM
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From: Kelowna BC
Its alright if there is a slight hissing during spinning, thats because the pistons in the caliper do not retract enough, as they are not "spring loaded" to suck the pads away from the caliper far enough, so the pad more or less just "leans" against the rotor. This is standard for even new vehicles, and cannot usually be heard over engine/tire/road noise, even at a slow coast.

Tire should spin freely by hand if it is jack up and in the air. Should definately spin more than 2-3 times on a one handed spin, unless you have no muscle fiber in your arm. :P.

The idling dipping down is just the brake booster putting a strain on the motor. Same thing when u put your headlights on, or turn up a "good" stereo. More electronics=more strain on alternator, same idea with the brakes and the brake booster.

Hope this helps.
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Old Jun 25, 2006 | 05:39 AM
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Originally Posted by Valkyrie
I didn't notice they were dragging until I drove around and when I got home I realized car wouldn't roll... lol.
If the brakes are working correctly, the car should be able to "roll", or move slightly if on a very slight incline. Check to rotors for high temps. You can check them with a heat temp gun, which most done have, or just feel the surrounding surface for a wheel that's hot, or hotter than the others. Don't touch the rotors as you may leave some skin on them if hot. You won't be able to spin the wheels around 2/3 times as there is too much resistance, esp. on the rear.

Best to check each caliper as if you're doing a pad replacement. On the fronts each piston should move easily into the caliper. If 4 piston, check the lowers carefully, as they will be the first to "freeze" as condensation sits at the bottom of the caliper. On the rears, see if the piston turns in freely. If all move as expected, no problems. If you find one that's tight, rebuild, or replace the caliper.

Another point-If you find 1 caliper where the piston(s) that won't move inward easily, open the bleeder and see if it will now move in, indicating an internally fractured brake hose.
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Old Jun 25, 2006 | 09:46 AM
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I had somewhat of the same problem. I always had issues with my breaks so i adjusted the pushrod length in the master cylinder to change the engagement point.
Well, the first time i adjusted it, i went to far and the brakes were on all the time. I ended up adjusting it many times before i got it right.

But anyway, the thing that i noticed that you should know is that my engagement point changed with the amount of vaccum on the booster. I would adjust it a little, jack up the car and see if it was rubbing; it would be fine, but then i would take it around the block and jack it up again and then notice it would then be rubbing...

If you want to adjust your pedal properly, your going to have to do it from both sides.
First, set your pedal to where you want it, then, adjust the master cylinder push rod so its not applying the break all the time. Mazda used a special tool to measure the pushrod length, but you can guess and check and get it about right; word of warning, it takes a TON of time. Also, a little adjustment goes a long way. Turning that pushrod adjusting nut 1/8th of a turn is the difference between a rock hard brake pedal with the brakes REALLY rubbing (to the point of the car stops for you!) and very little brakes at all.

I think, if you can feel the point here the brakes engagement point change as your driving, the pushrod is set to long and the brakes are rubbing.
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