6thgear

Hey guys. I just did my brakes and rotos myself. Now the front pads are rubbing on the rotor whole in motion.....I have done a search and what I found was maybe because the pads are thicker that the brake fluid is too high to release the piston....it was too high so I took some out to normal levels but the problem is still hapenning.
Some ppl have told me I need new calipers now...find it hard to believe and for fron calipers it's a forture. I got priced at 500 for both sides! I hope this is not the issue.

Please help me out. Thanks!

FastFreddy61

Did you mix silicone fluid with mineral, this will cause the rubber o ring around the piston to swell and prevent the piston from retracting. I have seen ppl use vise grips on the brake hose which deformed the hose enough to allow fluid to travel one way, but not back to the master cylinder, and ,brake hoses perish internally, small pieces of rubber block the returning fluid, but allow it ( fluid ) to move under braking pressure.

6thgear

I used a C clamp to push the piston in...never released any fluid and never had to add any....when I pushed the piston in it was back as far as it could possibly go and it was still a rough job getting it over the pads....I'm hoping that the piston just can't release far enough back to stop rubbing until pad wears down a bit making room for the piston to retract.........good theory?

FastFreddy61

Thats what I would do, or, not wanting to prematurely wear the rotors, maybe remove a very small amount of the pad material, I know its defeating the purpose of having thicker pads, but it may eliminate one theory .

Rtres09

are you sure you didnt accidentally bang against the dust shield causing it to rub against the rotor...i only say cuz its happend to me before...not on the 8...but on other cars....of course it would sound like a loud scrapping noise...not just normal braking noise....but its something to look at that wont cost 500 bucks....

good luck...if anything...your theory SHOULD work...IF the pad thickness is the problem

Winning 8

did you grease the sliding pins??? sometimes they get a little sticky and didn't move enough.

6thgear

Ya I'm hoping it will wear down....iv only put on 400km on it so far with the new set...I'm going to give it a couple weeks to see....but it is annoying so maybe I'll have to take a look sooner.

Thanks for the help!

6thgear

Quick question. The metal shim that goes on the back of the break pad.....is it needed? Or can I just put the caliper over the pad itself?

Race Roots

iTrader: (64)

Helps if you give more info about what pads and rotors you bought hawk has 2 thicknesses for the RX8. Also shims may not be needed depending on what pad you have purchased.

6thgear

Just a genaric pad...there super thick. With the shim on the back of the pad the breaks rub there's no where for the pad to move back. Just wondering if without the shim if the caliper piston will crack the pads.

Race Roots

iTrader: (64)

Have you installed brake pads before? If not I would find a good DIY and start over. I would recommend checking your slider pin bolts and bleed the system so you can move the caliper back further. That way you can seat the brake pads in there properly.

I wouldn't be surprised if you missed something along the way, but then again them being generic pads really cannot say they even gave you the right ones...

6thgear

True! I just greased the pins and evrything now...I don't think I'm going to put the shim on.

Rtres09

they can go on without the shim....theyre just suppose to help reduce brake noise

it is best to keep the shim though

Never L8

iTrader: (5)

Being generic, you probably Just got the wrong size pads. Mazda offered two different suspension options with two different sized rotors and pads. If you were sized for a sport suspension setup but have a standard suspension, that would explain your issue. Oh and I would keep the shims...just me.

Spin9k

Personally, from my experience, there is nothing wrong....I mean as long as you are not locked in one spot and the car doesn't move!

Every single time I've redone my brakes....(maybe 5 times) I have to push the pistons all the way in just to get the fit wide enough to get the pads and all back on the rotor. It rubs. You can hear the scrapping. It sounds like metal on metal (really pad on metal). It's normal. I'll say it again. It's normal. With the pad and all there, there is JUST enough room there to get it back over the rotor and that's just fine. When you are rolling at first it make the noise you speak of. No biggie. The car is fine. Just drive and after a fashion, the noise will go away. Or at least it has gone away every single time I've done the brakes and I'm still alive and driving and nothing... again ..nothing has every happened in 7 years.

Happy motoring...and kudos to someone who wrenches on their car.... does a man good!

6thgear

Hey guys. Thanks again for the replies I got a lot of great comments and have now become an expert with my brakes lol! After I greased the bottom and top sliders it has reduced the noise....just faintly there now. I'm sure it will wear off!