New Powerstop disc installed but can’t turn disc

[stiej1977]

Hi all

so I’ve installed a Powerstop front disc (z23) and Powerstop z23 pads on one front wheel so far. 87 vette. Job gone well except it was very hard to push the caliper back into place with the new pads on. Needed a light couple of taps with a rubber mallet to line the caliper up with the top slider mounting bolt.this was with having already pushed the piston in as far as it would go. I can’t turn the new disc by hand at all but can a little bit with a bar.
Is this right? Obviously everything is new and the pads are thick because they’re new. So should I expect it to be like this and when I do the other side and drive off to break everything in everything will free up enough to be good???

 

[FIVE RED]

I fitted Powerstop discs & pads like yours, but on my C5 some years ago. I can't recall if I couldn't turn the disc but like you I found the new thick pads a bit of a struggle to get onto the rotor. The Powerstop instructions state that there is a certain bedding in process which must be adhered to which involves hard braking at speed etc. I found a decent quiet road to carry out this procedure & have had no issues with the set up, best of all the rotors show very little signs of age after a few years, whatever the centres are coated with really does it's job.
Hope this helps.

 

[stiej1977]

Thanks. Yes the boxes are very informative on the break in method. Watched the videos in their site as well. Just feels strange that the discs are already “locked”. Obviously to the engine I guess it won’t even notice and after the break in period I guess it’ll free up. Hopefully!!!

 

[Oneball]

Break in has nothing to do with your issue. Something isn’t right.
Was the piston all the way in or just that you couldn’t push it further?
Did you take the lid off the master cylinder?

 

[stiej1977]

Yep piston couldn’t go any further and lid was off the fluid reservoir.

 

[Corvetteville]

Could it be dirt & corrosion on the hub behind the disc stopping the disc seating fully. It might be runout together with the thicker pads jamming the disc. I'd make sure the area is fully clean, and also use the wheel nuts to seat the disc fully

 

[Steven Smith]

Did you open the bleed nipple when pushing brake piston back to make sure it's fully retracted ?