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Pads Constantly Touch Rotors?

mle808
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mle808 Enthusiast

mle808

Posted
Posted

Hi all,

Got new rotors and pads installed over the weekend. All went well, feels very nice even with the lower spec QFM pads. (the QFM-HPX i wanted was 3 weeks wait)

I was wondering, when brakes are not applied in normal driving, are the pads meant to be constantly touching the surface of the rotor?

I thought this was odd, but then also wondered that, if the pads weren't constantly resting against the rotor wouldn't they be loose inside the caliper?

Also, if they were always touching...wouldn't that case excessive wear...or is there only minimal friction?

Please help with the above questions, its doing my head in.

Thanks!!

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https://www.sau.com.au/forums/topic/241027-pads-constantly-touch-rotors/
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Beer Baron Grand Master

Beer Baron

Posted
Posted

they will most likely be very lightly touching. jack or hoist the car up off the ground and the front wheels should be able to be turned freely by hand. you will hear a light dragging/touching noise, but you should not be able to feel any brake drag.

HackerX Community Regular

HackerX

Posted
Posted

Yeah it's normal:

http://auto.howstuffworks.com/disc-brake2.htm <- good read.

It's a side effect of floating calipers.

There would be minimal friction or wear since while the pad is "touching" there's no pressure from the brake pistons forcing the pad against the rotor. Without that pressure the pad is free to float far enough away from the rotor to allow it move freely, without it moving so far into the caliper that it requires excessive pedal travel to get it back against the rotor..

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