[ahakim24]

I recently replaced my brake rotors and pads, I went through the break in procedure n seemed ok. When I took the car up to a high rate of speed and went to brake I noticed that the brakes shutter and it is almost like warped rotors but seems to only be noticeable when the brakes get hotter. Any ideas?

[pikcachu]

Originally Posted by ahakim24

I recently replaced my brake rotors and pads, I went through the break in procedure n seemed ok. When I took the car up to a high rate of speed and went to brake I noticed that the brakes shutter and it is almost like warped rotors but seems to only be noticeable when the brakes get hotter. Any ideas?

Did you do it yourself ?

If you didn't clean the rotors well with brake cleaner maybe you had still oily residue from shipping and that overheats

[overcoil]

Always check the simple stuff first like proper bolt tightness: lug nuts, rotor retaining screw, caliper slide bolts etcetera.

[dradernh]

Originally Posted by ScottSinger

caliper slide bolts

FWIW, the front and rear M-Sport calipers are fixed.

[overcoil]

Originally Posted by dradernh

FWIW, the front and rear M-Sport calipers are fixed.

good point

then caliper mounting bolts

slide bolt probably couldn't cause vibrations as described

[ahakim24]

I got up to high speeds to try get a feel for what is going on. Once again when cold it feels fine. After a second they get hot n I loose brake power and it starts to shudder.

[ahakim24]

Originally Posted by ahakim24

I got up to high speeds to try get a feel for what is going on. Once again when cold it feels fine. After a second they get hot n I loose brake power and it starts to shudder.

.

[cooolone2]

Caliper is sticking...

[ahakim24]

Originally Posted by cooolone2

Caliper is sticking...

what should i do?

[aerobod]

Originally Posted by ahakim24

what should i do?

First the easy confirmation of a seized/sticking caliper, carefully put a hand near the centre of the wheel after driving the car and compare with the heat coming from the wheel on the same axle on the other side. You may be able to quickly touch the end of the wheel bolts, but there is a risk of burning your fingers if you are not careful. Any difference in the heat from side to side on that axle is a good sign of a stuck caliper.

A rebuild (if the pistons and bores are in good shape) of the caliper or replacement is needed. If you have done it before you can replace or rebuild yourself, if not a BMW specialist is a good bet to do the work.

[ahakim24]

Originally Posted by aerobod

First the easy confirmation of a seized/sticking caliper, carefully put a hand near the centre of the wheel after driving the car and compare with the heat coming from the wheel on the same axle on the other side. You may be able to quickly touch the end of the wheel bolts, but there is a risk of burning your fingers if you are not careful. Any difference in the heat from side to side on that axle is a good sign of a stuck caliper.

A rebuild (if the pistons and bores are in good shape) of the caliper or replacement is needed. If you have done it before you can replace or rebuild yourself, if not a BMW specialist is a good bet to do the work.

The rotors are identical on both sides. Both have these hot spots

[aerobod]

Originally Posted by ahakim24

The rotors are identical on both sides. Both have these hot spots

If that is the case, going by the uneven heating in your photo, they may have been broken in incorrectly due to the lack of an even pad deposit, I would follow the pad and rotor manufacturer break-in procedure, as they are not all the same. The other issue may be variable rotor quality, if they are not a BMW or OEM supplier to BMW part.

[ahakim24]

Originally Posted by aerobod

If that is the case, going by the uneven heating in your photo, they may have been broken in incorrectly due to the lack of an even pad deposit, I would follow the pad and rotor manufacturer break-in procedure, as they are not all the same. The other issue may be variable rotor quality, if they are not a BMW or OEM supplier to BMW part.

I appreciate your help! They're Zimmerman rotors from fcp euro and brembo pads that are from Amazon but I wonder if they were fakes or something. I hate to do it but brakes are not something I wanna chance with. I'm gonna order a new set of rotors and the ebc yellow pads

[overcoil]

Originally Posted by ahakim24

what should i do?

If u did the work yourself.

Disassemble, and reassemble carefully using proper or as close to proper torque specs as possible. Clean the hub surface with scotch-brite and use/get new caliper mounting bolts. Inspect all surfaces, pads, rotors, hub and confirm anti rattle or mounting spring is installed correctly.

Also do a break flush and start by siphoning old fluid out of master cylinder reservoir.

I do not use brake cleaner on rotors. If your rotors come encased in wax eradicate as the instructions state.

Also, I don’t recall on my BMW but caliper pistons can be retracted two ways 1) by rotating or 2) being pressed straight in. So be sure the piston rubber is seated properly.

Then retest brake performance on the street.
Always do the easy stuff first.

[ahakim24]

Originally Posted by ScottSinger

If u did the work yourself.

Disassemble, and reassemble carefully using proper or as close to proper torque specs as possible. Clean the hub surface with scotch-brite and use/get new caliper mounting bolts. Inspect all surfaces, pads, rotors, hub and confirm anti rattle or mounting spring is installed correctly.

Also do a break flush and start by siphoning old fluid out of master cylinder reservoir.

I do not use brake cleaner on rotors. If your rotors come encased in wax eradicate as the instructions state.

Also, I don’t recall on my BMW but caliper pistons can be retracted two ways 1) by rotating or 2) being pressed straight in. So be sure the piston rubber is seated properly.

Then retest brake performance on the street.
Always do the easy stuff first.

Thanks, I did the first steps you mentioned already and had no change. Brake fluid was my next thought but I never had an issue with it on the prior pad setup so I don't think that's my issue. Thank you for your suggestions!

[aerobod]

Originally Posted by ahakim24

I appreciate your help! They're Zimmerman rotors from fcp euro and brembo pads that are from Amazon but I wonder if they were fakes or something. I hate to do it but brakes are not something I wanna chance with. I'm gonna order a new set of rotors and the ebc yellow pads

The Brembo guide to spotting fakes has some info on pads specifically, at the bottom: https://www.brembo.com/en/company/ne...ognizing-fakes

[dradernh]

Originally Posted by ahakim24

brembo pads that are from Amazon

Which Amazon vendor sold you the pads?

I wouldn't buy Brembo components from Amazon unless the vendor could be confirmed to be an authorized Brembo supplier.

[ahakim24]

Originally Posted by dradernh

Which Amazon vendor sold you the pads?

I wouldn't buy Brembo components from Amazon unless the vendor could be confirmed to be an authorized Brembo supplier.

yeah i quickly learned that. the vendor was "new parts". i never noticed until a few days ago.

[XutvJet]

Describe your break-in procedure.

[TrboMike]

Originally Posted by XutvJet

Describe your break-in procedure.

I agree, I think you overheated the shit out of them when trying to break them in.

[ahakim24]

Originally Posted by TrboMike

I agree, I think you overheated the shit out of them when trying to break them in.

I'd bet you're correct lol. I drove fairly easy for about 100 miles then well... I didn't 😂

[TrboMike]

Most of the time when you have pads on a rotor that wasnt before (new pads, new rotors, or hopefully both new) on the first drive you want to overheat the shit out of them WITHOUT STOPPING THE CAR then "cool" them by not touching the brakes while moving for a long period. Basically you want them very hot so they mate together, heat cycle together, and then cool down slowly. If you come to a stop while they're hot, the pads start depositing material on that one spot on the rotor, and the rotor is increasing in heat where the pad it touching it while decreasing in heat everywhere else. Not good.

If you do get them hot as hell and then slowly cool them on the first drive, they are now both heat cycled and "bedded" or "mated" to each other. Supposedly you will get better braking and they last long and less chance of making hot spots or warping in the future.

When I do brakes, what I do is drive gently to the nearest highway and hopefully the onramp has no traffic light. You drive like an ass near the entrance ramp with 40 to 1mph stops, then 60 to 1mpg, then 90 to 1mph at this point you should feel the brakes losing bite by overheating and maybe even smell them if they are aggressive pads. I said 1mpg instead of 0mph because you DONT want to stop while the brakes are overheated. Then you get on the highway and set the cruise control to a speed less then traffic so you never have to touch the brakes and drive 20-30 min so your overheating brakes are now spinning in cool 65mph air and cooling down slowly.

If you get caught at a light or stop sign, just roll forwards and backwards as much as you can you really dont want that blazing hot pad to stop on the rotor.

When you say "I didnt" did you overheat them and then park the car? No es bueno.