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> Brake Pad Dragging on Front Rotor, Speader Spring Installed Wrong?
VWTortuga336
post Sep 13 2015, 08:24 PM
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Just installed freshly rebuilt calipers with new pads and hardware on my '74. Now the pad closest to the inside of the car seems to be rubbing on the rotor. I was thinking maybe I had the spreader spring installed incorrectly, but I can't even push the pad back any further by hand either.

Any thoughts on what would cause this?

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stugray
post Sep 14 2015, 09:05 AM
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I don't believe the "spreaders" actually do anything to help the pistons push out.
The knockback is achieved by the natural runout in the rotor as it flexes.
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mgp4591
post Sep 14 2015, 09:17 AM
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QUOTE(stugray @ Sep 14 2015, 09:05 AM) *

I don't believe the "spreaders" actually do anything to help the pistons push out.
The knockback is achieved by the natural runout in the rotor as it flexes.

That and the square cut seal between the caliper body and the piston. The seal holds back the fluid but it can't overcome the fluid pressure when the pedal is depressed- it only flexes slightly when the brakes are actuated then after the pressure is release, the seal pulls back on the piston until it the flat part is on the piston surface. Gives it a couple of thousandths for the pad to move away from the rotor surface. If the pad isn't dragging on the rotor face, drive it a few miles (20 or so), then check the clearance again. You'll know if the piston is hanging up or not. Good luck!
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