[Lanesky]

Hey all, recently I replaced the back brakes on my Mazda 3 GT sport. I went with Centric premium discs and ceramic pads. Everything fit fine and for a little bit brakes worked fine. The pad bite I felt wasn't as good as oem but its the rear and hard to really tell. But not too long after and still now at 70km/h and above if I lightly apply the brakes the judder is quite noticeable. If i brake hard from 120km/h down through 70 the judder is crazy. The instructions said with ceramic pads there isn't any real brake in procedure as if they were performance pads. Did I bed them in wrong? rotors no good? In hindsight I could have just replaced the pads but when it had it's last dealer service they tried to sell me on a 600 Canadian peso brake job and I said no thanks but figured they were right about doing the pads and rotors at the same time. Any ideas how to remedy this? I know getting rotors turned isn't great either. less meat less heat and all that so maybe switch to a more aggressive pad?

Thanks!

 

[MrBen]

Hey all, recently I replaced the back brakes on my Mazda 3 GT sport. I went with Centric premium discs and ceramic pads. Everything fit fine and for a little bit brakes worked fine. The pad bite I felt wasn't as good as oem but its the rear and hard to really tell. But not too long after and still now at 70km/h and above if I lightly apply the brakes the judder is quite noticeable. If i brake hard from 120km/h down through 70 the judder is crazy. The instructions said with ceramic pads there isn't any real brake in procedure as if they were performance pads. Did I bed them in wrong? rotors no good? In hindsight I could have just replaced the pads but when it had it's last dealer service they tried to sell me on a 600 Canadian peso brake job and I said no thanks but figured they were right about doing the pads and rotors at the same time. Any ideas how to remedy this? I know getting rotors turned isn't great either. less meat less heat and all that so maybe switch to a more aggressive pad?

Thanks!

When it comes to some aftermarket stuff....not all are as good as OEM, unless they're known for quality. The rotors is the issue there.

 

[Gary_L]

You should search for the break-in procedure for ceramic pads, because they have to be heated and bedded properly upon initial installation. Either you missed the break-in procedure on the packaging/enclosed instructions, or they weren't provided. I installed ceramic pads, along with slotted rotors, about a year ago, and the pads had break-in instructions.

Based on the symptoms you're describing, the rotors are most likely warped. Turning rotors is a waste of time and money because: 1) you want as much meat as possible on them; and 2) rotors which were warped have a greater likelihood of warping again once heated after normal operation.

Overall, you're better off getting new rotors and pads, making sure all proper break-in procedures are followed.

 

[arathol]

Overall, you're better off getting new rotors and pads, making sure all proper break-in procedures are followed.

No need for that just yet if the rotors are new. Chances are the pads were not bedded properly and there are uneven pad material deposits as a result. Get the proper bedding procedure and follow it. More often than not all you need to do to fix this sort of problem is do a few hard stops from varying speeds up to 60 mph without coming to a full stop, get the brakes good and hot, then drive around normally for a bit and let the brakes cool off. No full stops and no hand brake until the brakes are at normal temps. This should remove any deposits and get the brakes working as they should.

 

[Gary_L]

No need for that just yet if the rotors are new. Chances are the pads were not bedded properly and there are uneven pad material deposits as a result. Get the proper bedding procedure and follow it. More often than not all you need to do to fix this sort of problem is do a few hard stops from varying speeds up to 60 mph without coming to a full stop, get the brakes good and hot, then drive around normally for a bit and let the brakes cool off. No full stops and no hand brake until the brakes are at normal temps. This should remove any deposits and get the brakes working as they should.

According to one of these links, the rotors wouldn't have warped; however, the Power Stop Brakes links says it's possible. If the rotors aren't warped, then they'd have to be skimmed, but ceramic pads can't/shouldn't be reburnished. Ultimately the OP would be better off verifying the rotors aren't warped and, if not, have them cleaned. The pads should be considered a loss. Brakes are one item I'm not going to fudge on parts as it's cheaper to cut one's losses on the price of pads versus potential property damage or harm to people.

DISC PAD AND BRAKE SHOE BREAK-IN (BURNISH) PROCEDURE

Brake Pad Bed-In: The Crucial Forgotten Step

 

[Lanesky]

Thanks for the replies. I have tried to properly bed in the brakes as if they weren't ceramic as friends have said to do. I did the procedure as per the centric FAQ section today multiple brake applications until fade but never fully shopping with a light drive home never stopping fully. but theres no change. Maybe theres not enough heat build up since it's the rear brakes even with EBD? I'm leaning towards living with it until I can save up and better parts. All said and done this was 160 cdn from rockauto. Their performance line would have been high 200's but maybe more worth it..

 

[arathol]

Get a dial indicator like his one- https://www.harborfreight.com/clamping-dial-indicator-63656.html

Check both sides of all four rotors. That will give you an indication of the real problem.

 

[Lanesky]

Get a dial indicator like his one- https://www.harborfreight.com/clamping-dial-indicator-63656.html

Check both sides of all four rotors. That will give you an indication of the real problem.

Good call! I'll see if I can borrow one from work. I did just have a thought. Maybe I didn't clean the hub well enough? when I put the discs on the hub I held em there with three nuts and spun them I could see run-out. I just figured since the wheel wasn't pressing up against the hat of the rotor to the hub it wasn't a problem. But How would the rotor come out of the box warped enough to see it? first time I've had this happen with new parts.

 

[gregersonke]

If it's really happening when you press hard that would be the front rotors and not the rear. An easy way to check rear vs front. Pull the ebrake at speed, not all the way, but enough to apply application then apply more. If you get the judder then it's your rear. If it's not then it's your fronts. OEM rotors tend not to be the best ones out there. The fronts aren't exactly awesome either.

 

[Lanesky]

If it's really happening when you press hard that would be the front rotors and not the rear. An easy way to check rear vs front. Pull the ebrake at speed, not all the way, but enough to apply application then apply more. If you get the judder then it's your rear. If it's not then it's your fronts. OEM rotors tend not to be the best ones out there. The fronts aren't exactly awesome either.

I have always gone with the thought process that if it comes through the steering wheel its the fronts and if I feel it in the rump its the rear. I'll give that a try tomorrow on the way to work though. Thanks!

 

[gregersonke]

Generally, that's the case. But with the electronic power steering, it can really numb the feeling a bit. Also, these cars use the braking differently than most opting to use the fronts for heavy braking and the rears for everyday braking. So you almost never use the front until you get on the brakes hard. I've got 172k on the original front brakes. Doesn't beat my drums on my honda odyssey that are still going almost 300k into them.

 

[Lanesky]

Good points. At next service I'll have the stealership have a look since I cant borrow a dial caliper from work and see what gives. I had to put a summer wheel on my car tonight since the winter setup had a big nail in it and looking at the rear discs they haven't even worn of the cross hatch pattern... these pads are very gentle. Too gentle. Crap. Should have just went oem.

 

[gregersonke]

My fronts were slightly warped around 120k I've lived with them and I have 175k on them and the pads.