Brake Rotor Rust Spot where Rotor Meets Pad - Endless Racing Mono6

[Hella_GTR]

Good morning folks, looking for some help on how to treat my new Endless Brakes.  I recently upgraded my bcnr33's brakes to Endless Racing Mono 6.  All was good until I washed my car and parked it overnight and drove it the next day to work and the brakes felt like the rotors were warped shaking about and the pedal pulsing.  I took a look and found these rust spots on the rotors as shown below.  It looks like where the pad meets the rotors, rust formed overnight.  I spent a week daily driving for 250kms, doing hard braking as often as I can when the opporutnity allowed.  It got better but still the rust spots remain and the pedal pulsing remains.  It's been humid here in Japan so it must've rusted bad overnight.  Anyone have experience with this?  I'll keep pounding on the brakes whenever I can but I feel i've done that enough.  My pads are endless street spec so not too aggressive.

 

I was thinking about hitting the rust spot with a flex-hone but don't want to do that if I don't have to.

 

If anyone has any advice, I'd appreciate it.  Thank you!

P.S. The last photo is before the rust occurred just to show off how beautiful the brakes are.

 

Info on the brakes: https://www.endless-sport.co.jp/products/brake_caliper/index_RacingMONO6.html

[GTSBoy]

Remove pads. Scuff them back on some very flat, slightly rough but not too rough concrete, put them back in and attempt to bed them in again. If that doesn't work, discs off, onto disc lathe and give them a little skim. As well as another scuff of the pads.

[Hella_GTR]

On 7/22/2022 at 9:00 AM, GTSBoy said:

Remove pads. Scuff them back on some very flat, slightly rough but not too rough concrete, put them back in and attempt to bed them in again. If that doesn't work, discs off, onto disc lathe and give them a little skim. As well as another scuff of the pads.

Dang, I was hoping just hitting the spot with a flex-hone would work.  That means I gotta go to a shop cause Tokyo living means I'm in a tower with a vending machine parking lot and no place to do that kind of work myself lol.  

Thanks for the guidance.  Surprised this happened in the first place.

[joshuaho96]

On 7/21/2022 at 5:11 PM, Hella_GTR said:

Dang, I was hoping just hitting the spot with a flex-hone would work.  That means I gotta go to a shop cause Tokyo living means I'm in a tower with a vending machine parking lot and no place to do that kind of work myself lol.  

Thanks for the guidance.  Surprised this happened in the first place.

Gotta be careful with brakes when it comes to washing cars unfortunately. I'm surprised that hard braking didn't clean the rust off though.

[Hella_GTR]

On 7/22/2022 at 11:32 AM, joshuaho96 said:

Gotta be careful with brakes when it comes to washing cars unfortunately. I'm surprised that hard braking didn't clean the rust off though.

It's just strange because I've washed my car 100 times and this never happened before.  The car is parked underground as well so I don't really get what happened.  We did have some pretty serious flooding/rain before the wash and it was humid as heck but still.  I did park it like right after washing though.  I'm also disappointed that this happened since the brakes were ￥￥￥￥￥￥￥￥

[joshuaho96]

On 7/21/2022 at 7:39 PM, Hella_GTR said:

It's just strange because I've washed my car 100 times and this never happened before.  The car is parked underground as well so I don't really get what happened.  We did have some pretty serious flooding/rain before the wash and it was humid as heck but still.  I did park it like right after washing though.  I'm also disappointed that this happened since the brakes were ￥￥￥￥￥￥￥￥

It's fixable, just get the rotor and pads scuffed/cleaned off with some sandpaper. Annoying but I wouldn't bother with new pads/rotors just yet.

Edited July 22, 2022 by joshuaho96

[Hella_GTR]

On 7/22/2022 at 11:41 AM, joshuaho96 said:

It's fixable, just get the rotor and pads scuffed/cleaned off with some sandpaper. Annoying but I wouldn't bother with new pads/rotors just yet.

That's the plan.  No way I'm giving up on these new expensive rotors lol.  These are times I wish i had a house with a garage to work on a car.  

Thanks man and I gotta get an update from you on your progress.  Next for me is a Nismo intercooler. I'm still hoping for a California plate in the future...

[Hella_GTR]

I talked to Nismo and they said I need to go do some more back-to-back high speed hard braking. If that doesn't clear it then I need new rotors and pads which would suck.  

[Duncan]

I think the advice on some really hard braking to get the brakes stinky hot is good.

The advice to buy new pads and rotors is bad. If getting them hot doesn't work you need to just get a mechanic to skim the discs as said above. I'm pretty confident the rotors are warped, that's why the surface rust isn't getting wiped off straight away.

BTW it is perfectly normal for a brake disc to grown surface rust overnight if it gets wet, it gets wiped off as soon as you use the brakes

[Hella_GTR]

On 7/22/2022 at 1:48 PM, Duncan said:

I think the advice on some really hard braking to get the brakes stinky hot is good.

The advice to buy new pads and rotors is bad. If getting them hot doesn't work you need to just get a mechanic to skim the discs as said above. I'm pretty confident the rotors are warped, that's why the surface rust isn't getting wiped off straight away.

BTW it is perfectly normal for a brake disc to grown surface rust overnight if it gets wet, it gets wiped off as soon as you use the brakes

Sounds good I'll attempt some hard braking back-to-back from high speeds.  It's actually really hard to do that in tokyo area but i'll find a way lol.  

The brakes setup is pretty new, like no more than 8,000 kilo's on them.  I've definitely encountered surface rust from washing the car or rain, but nothing like this.  It was like flooded the same weekend I washed it though and drove through some pretty deep puddle but thought it would have dried out by the time I got home.  I hope the rotors are not warped.  The rust is only where the pad met the rotor overnight.  So when it hits that lifted rusted spot, you can hear it and feel it when braking...

Thanks for the advice.  It sounds salvageable!  

Edited July 22, 2022 by Hella_GTR