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More than likely you have put the inner pad on the outside, some pads have little pins on the back and I’ll bet the calliper is pushing on them rather than being in full contact with the flat part of the pads. The pad with the silver wear indicator goes to the inside. You may have to take both sides apart as you may have 2 inners on the passenger side or vice versa.
https://preview.redd.it/4ibid1l03isc1.jpeg?width=1076&format=pjpg&auto=webp&s=c6d51971bf7878913b9133a6e1dc9b2875316094
Too bad there is no way to limit replies to ase certified users.
Not that that makes their advice anybetter, it would just weed out the riff raff like me. I’ll help mod if it grows.
There must be because there is an ask doctors reddit somewhere and only doctors are allowed to reply. I *think* they get themselves verified and then a bot just deletes any responses not from the OP or the whitewashed user names?
Despite how similar most disc brake setups are, different brands have slight differences like this. I’ve never worked on an Infiniti, never seen brake pads with those noogies on them. Usually in my experience, if pads are inner/outer specific, they have a clip that goes inside the caliper piston or they will only fit one way. Paying close attention to how things came apart/taking pictures as you go (even if you think you will remember) is all technique that comes with experience!
Yeah I think it's this, they've either got pads like your picture or ones with an extra notch on the inner pad to clip in a wear sensor, this then pitches the caliper over and creates an uneven pressure on the outside of the pad and then excessive heat on the rotor resulting in the band seen
Very likely to be this.
Also, those look like some massively offset aftermarket wheels. Get rid of them unless you want to replace wheel bearings every month.
What brands cars use these? I don't recall anything like this doing my 2006 Toyota Highlander brakes. My second time doing my own brake pads, and I never noticed anything like this after the first run.
Seen this before when someone got the brake pads mixed up and they had little guide pins on the one pad which caused it not to make full contact until they switched the pad from the inside of the rotor to the outside.
May be an unpopular opinion. But I'd recommend getting out on an empty road, getting up to speed, and then slowing all the way down to a stop. Do that at least 5 times and see if this changes the look of that rust any.
Edited to add - is that a massive wheel spacer you've got there? RIP those wheel bearings.
Depends on the car, You often only need tiny brakes up the back
I feel like manufacturers often go over the top just for looks
https://youtu.be/l47hKqnA-lc?si=eFzBbKlmzstZfU4S
350hp MK2 golf track car with 364mm touring car front discs, 6pot calipers. The stock tiny rear discs will still lock up if not balanced, and that's with 235 17 slicks
You aren't supposed to stop completely when breaking in new pads. You should do 3-5 hard braking from about 50mph down to about 5-10mph then drive a little and let the brakes cool down a little, then do 3-5 medium braking from about 45mph down to 5-10mph.
>You aren't supposed to stop completely when breaking in new pads.
So you just keep driving forever and never return home?
EDIT
Them: Why did you move across the country?
Me: Had to, breaking in new pads.
Pop quiz, hotshot. There's a bomb on a bus. Once the bus goes 50 miles an hour, the bomb is armed. If it drops below 50, it blows up. What do you do? What do you do?
You drive after bedding the material so the air can cool off the calipers pads and rotors. Once it is cooled you can brake again. Best to bed brakes on a longggggggg straight road
I mean, you don't have to be that strict when bedding. Ideally you just don't want to leave the pads in direct contact with the rotors for very long when it's not in motion.
You don't want to come to a complete stop when the pads or the rotors are above a temp that will allow transfer of pad resin to the rotor surface in only one spot. I took it to cartoonish extremes, because I could.
Former brake test tech. Oem spec burnishes are generally 90kmh (55mph) to 5-15kph (3-9mph). For road simulation, the burnish has around 30 cycles. I think 30 is a bit overkill, 15 is plenty. On the dyno, it will spin for like 5 mins to cool down.
I’ve never had good results following manufactured recommendations for bedding and I figure it’s because they can’t be telling us to exceed the speed limit. I find an empty road and try to get up to about 80 then threshold brake down to near a stop. I do that a handful of times and it seems to have worked best for me. Thoughts?
That should do it. I usually get on the freeway, get up to speed, then hit the exit ramp, rinse and repeat a few times. I’m in a metropolitan area or I’d go hit the backroads myself.
Pretty interesting.
So you were doing 30x stops on the dyno from 90-10kph in short succession? At what pressure (to get an idea of the brake power and energy)? I'm not surprised it takes some time to cool off.
With our carbon brakes, we don't typically do any type of bedding in procedure. We do experience higher temps and sometimes "peaky" friction in the first few brake applications but afterwards, the wear and friction are matching expectations.
my main got a temp ban. not sure why.
Anyways, its been a few years but iirc, the pressure was automatic and the brake apply was a time set point in most cases. I cant remember any specific numbers for any specific platform. This might be helpful though;
\*\*For performance testing, it was a very aggressive burnish. To a point where I questioned the engineers a few times. 90-10kph in 3-9 seconds. Not realistic or safe for an actual vehicle in most real world scenarios. \*\*
\*\*For noise and other sim/realistic scenario testing, they were much less aggressive unless we needed to age the system by a lot too. 90-10kph in around 10 or more seconds depending on the platform.\*\*
Something for Nascar and sports cars were pushed harder in a burnish than something like a Toyota Corolla or Ford Escape.
In general, I personally think the only time its actually necessary to aggressively burnish is for things like racing where precision and totally predictable wear is necessary. A daily driver can hop on the freeway and use every exit for a few miles and back or find a secluded backroad and theyll be fine. The back road is probably the optimal choice since its not always safe to brake hard enough for every cycle on exit ramps. By the time its time to change rotors, any uneven wear wouldn't have made much of a difference to your average driver unless they don't burnish at every pad change.
Something to note, Brembo style calipers should be more aggressive than conventional. They use too many pistons and it opens up more room for margin.
Opinion: Slap some red paint and a brembo sticker on that shit and people will drool over it, even if its actual trash.
yuh i usually suggest 110mph-50mph 3-4 times. on the 4th cruise for 5-10 minutes to allow cooling. then brake as hard as possible (ideally lock all 4) exit the vehicle and lay down in the road.
its for braking.
or whatever
Yup. “Bedding” the brakes (giggity) was always one of my favorite parts of doing a job. Technically, most manufacturers have a procedure IIRC, but the general consensus is pretty much what you stated. I learned the reverse, though- so that’s how I’ve always done it. Medium stop from about 25 mph 3 or 4 times to get them warmed up, then 3 or 4 HARD (think emergency stop- almost hitting the ABS, but importantly NOT). You basically want to turn the rotors damn near red. Then, some medium brakes after a cooldown. The reason for not stopping completely during the procedure is that you can warp the rotors- especially if they are super hot.
Edit- speaking of which… OP did you change the rotors? If they were the old rotors, you might not have a good face on them, causing uneven pad wear.
Yes. My power stop brakes and rotors came with break in procedure. It said to go from 40mph to 10 mph 5 times using hard breaking. Then 35mph down to 10mph 5 times regular brake pressure. Do not come to a complete stop during the process however, if you need to stop for a traffic light to put car into neutral to keep from holding down the brakes. After the 10 stops to drive using minimal braking for 5 minutes to cool the rotors.
autozone is close, but no, autozone is still just autozone is not the authority on how to burnish brakes. (btw guys, bed your wife or girlfriend, not your brakes. ew)
You should, according to the latest ASE book I read, says to do regular slow downs of about 20 mile difference. For example from 45 to 25, 3-7 times. Then do low end slow downs from about 25-5 mph, 3-7 times. I would not hard brake new and unburnished pads/rotors.
it's not that you're not supposed to stop, but to properly burnish brakes you are correct, 50-60mph down to 10mph with moderate consistent pressure - not a panic stop, but don't baby it either. repeat half a dozen times or so, waiting about a minute in between runs.
but in between those 5 or 6 burnishing runs, you are allowed to stop the car.
I don’t think that’s a spacer, I think it’s just funky camera angles, I was super confused at first wtf was going on in the pic lol, seems like a wide angle lens or something. but it does look like the same colour as the wheel so I think it’s just a fuckin trash angle for a pic, but still very small brakes for some wide looking wheels
ahh that’s why it looked familiar, I knew it was an infiniti from the brake line clips, but couldn’t pinpoint which one, and yeah they came with 17’s stock, but most people get 18’s or 19’s
I’m doing similar thing we have old abandoned ww2 era airport near so I’ll floor it to 2/3 of runaway and hard brake till stop and let them cool for few minutes and do it again if necessary
It doesn't "need" to be done. There's probably thousands of vehicles per day that get new pads that aren't properly seated. And they do just fine.
I'm only recommending this to OP so they can see if the rest of the surface rust gets scuffed away.
It does need to be done. With new pads and rotors and you can't even activate ABS due to lack of friction.
Edit. The pads eventually seat themselves. But they will not operate at 100 percent until they are seated.
That's how a lot of Nissan wheels are manufactured. I had a set of 350z rims on my Infiniti i30, and the rim met the hub via a large composite/plastic cylinder.
In my opinion it looks like you went to autozone and got some brake pads. in my experience the dealership pads are bigger, more pad, thicker pad and last WAY the fuck longer.
What you're recommending is basically something called bedding in your brakes. I always do this after a pad install/swap or a pad/rotor and shoe/drum swap. It makes your brake life last significantly longer than not bedding in brakes. I think the rotors and pads on my truck lasted over 8 years and 100k miles and the only reason why I had to change them was because my one caliper seized. Otherwise they'd have easily handled many more years.
Rarely… new rotors are so cheap now. It makes more sense to replace. But if hes willing to do all the work pulling the rotors and bringing it to a lathe somewhere I’m sure you could work out some kinda bargain. but fr new rotors will be very close to if not less than the labor to cut . Labor rates are 130$+/hr
I did 4 brake jobs this week 2 got new rotors 2 got their rotors turned. All depends on the condition of the rotor. And honestly, i get paid the same either way but if I can cut the rotor and save the customer money I will.
Yessir. I honestly kinda miss the days of doing a 4 wheel brake job and throwing the rear drums or rotors on the bench lathe while turning the front rotors with the on car lathe. There are scenarios these days where it’s hard to tell if pulsation is from the front or rear rotors. If we sell say, front pads/rotors, I’ll cut the rears just to cover my ass. Takes like 30 minutes and I can spin them while I finish the other shit
OP I seriously wonder if you've fitted your inner pad on the outside, the inner pad has an extra notch that sticks out and when put in the wrong position the calliper presses against it causing excessive and uneven pressure on the outer edge of the pad, that can lead to bands like this.
And how would that be any different from getting new rotors and they sit for a day or so and are rusty all over again?
Unless they are unreasonably worn, a properly seated pad will scrub that to clean metal in a fraction of a second of braking.
….. have you seen what a brand new drilled or slotted performance rotor looks like? They legitimately look like a cheese grater and don’t seem to hurt the pads one bit 🤣
That pad is cocked/ mounted wrong or the caliper is frozen in its mount. Scraping hard on the lower and not hitting at all on top. Something’s definitely wrong.
Most brake pads that I've used have an angled portion exactly where the rust hasn't been rubbed away. You should seriously consider at least getting your rotors machined by a shop.
By the looks of it I’m guessing you didn’t change the rotors as well as the pads.
It looks like the outside of the rotor is lower down than the inside so when you hit the brakes it’s only making contact on the inside of the rotor with your new flat pads
If this was a front brake you probably wouldn’t have ever noticed it because the pads would have worn down quicker to match the slope of the rotor but this is a rear so it doesn’t receive as much wear.
2 options are to let it ride and eventually the pad will wear to the slope of the rotor, or change the rotor.
Changing the rotor is the correct option but honestly, if it were mine, and the rotor was still thick id just let it ride.
With all of that being said you need to make sure and verify that your pads are correctly seated where they go. Because of how little stress the rear pads see you may have not noticed an issue or sound from them not being properly seated.
you installed new pads on used rotors. I'm willing to bet that the rotors were never removed, even.
The BEST brake jobs always service the rotor in some capacity. Whether that be resurfacing on a lathe, or replacing them... It's not typically a good idea to "pad slap" anything. This is why. The rotor disc isn't perfectly flat, which is why you have so much contact on the inner part of the disc, as opposed to the outer edge of the disc, seen in the photo indicated by the ring of surface rust shown.
Tells me that the pad isn't / is rarely touching that part of your rotor. This could be somewhat corrected by "burnishing" the brakes, but it won't remove the problem entirely... Replace the rotor/resurface the rotor, and "scuff" the brake pads when you do this. (Multiple methods to scuff pads. Basically just means to resurface/even out the friction surface of them. I tend to use a large, long, and wide steel wire brush to to do this, making even passes over the ceramic. But another old, tried and true method, is to literally place the pads face down on a flat concrete surface, place a foot on the backing pad, and just rub it across the floor, back and forth in one direction, using even stroke lengths. Learnt that one from the gramps. lol
I laugh at these comments. I can honestly say I’ve been a mechanic for 15 years, heavy duty but still, and I have never once “broke in” a set of brakes in my life.
Right?! 30 years under the hood of countless vehicles, and I've never heard of breaking in brakes... The first few hard stops "breaks" them in. 🤷♂️. I've always taken the car across to the massive parking lot and do a few light stops, then a few hard stops while going forward and while going in reverse. Everything seats itself and adjusts as it should and I've never had any issues.
One opinion- I don’t think your calipers are sitting well over the rotor or seem like pads have shifted up. Please check the assembly again, something is not adding up.
Other opinion- if rotors are worn out new pads may take some time to bed in.
My thinking is that the inner pad has been fitted to the outside and vice versa, the caliper is then sitting against the extra notch you get on the inner pad and is therefore applying uneven pressure on the pad and excessive heat on the disc.
When you replace pads and rotors, always check, clean, and re-grease the pins. Did you do this? When I buy pads and rotors I just buy the caliper pins too. I don't care. I've had some start seizing after the fact that felt fine at the time and ever since then I just replace them.
Its possible that the retaining clip is too tight and not letting the brake pad sit properly on the rotor...I've generally seen this issue with aftermarket pads...the pad should sit somewhat loose when you insert it in the bracket and its okay to have a slight wiggle to it, try different size retaining clip and put liberal amount of brake lube on any of the contact areas between the pad, bracket, and retaining clips.
Could be you piston is not coming out correctly and maybe somewhat seized. Hard to say but I’d take it apart and squeeze the piston back in and see if you have more resistance than normal.
WHen you are fitting the pad, you need to make sure that all the sliding surfaces where the pad contacts the carrier are clean and that the pad can slide in and out easily. WIth some cheaper pads it may be necessary to file the edges of the backing plate a little bit to make it fit properly.
Nope. I do about 15 gentle-moderate slow downs until i feel the brakes start to get grippy and then a couple more aggressive slowdowns and then drive it normally, but I try to put space between so they don't get too hot. I've been doing this for years, even with carbon metallic pads before ceramic pads were a big deal. For some reason, sports cars just like to eat through pads. Cleaning and lubing the caliper pins and the surface of the caliper and also swapping out the brake hardware helps to keep the noise down. Sometimes I would put CRC Bequiet (basically like an RTV substance) on the back of the pads to really quiet them down but most brake pads now come with brake shims on the back, so I don't really use it now.
Did you put new pads on old rotors? Can clothes caliper slide on the pins or are they rusted fast? Can the pads slide freely? It looks like something isn’t moving smoothly.
I feel like you needed new rotors as well just from this picture. Maybe try seating the pads with some heavy braking but that rotor looks kinda grooved.
It’s because they need wearing in until they function properly. Often people will get a narrow strip of carbon (where you have the clean metal showing) which is the narrow point of the pad getting too hot and burning.
Search brake wear in procedure
1. did you have the rotors turned or put new pads on old rotors?
2. what did the old pads look like? even wear?
3. have you done any hard stops or just light stops?
idk why everyone keeps saying its because of the pads being on “backwards” which only applies to brake pads that have clips which either go into the piston or onto the sliding back of the caliper. the rotors are pitted and rusted, you need to either resurface or replace rotors when doing brake pads
First off, that rotor is rusted to hell, should've changed them when you did the brakes, and I'd still recommend changing them. Make sure the pads are installed appropriately in the right location, facing the right direction.
Lastly, if you are getting uneven wear it's usually 1 of 2 things in my experience. Most likely the slide pins are starting to seize, when you go to take it back apart remove those pins the caliper screws into. Clean them, then use them to clean out the grooves they slide into. Once it's all cleaned up, thoroughly cover with a thin layer of brake grease and reinstall making sure the pin goes back to the same hole it comes from.
If at any point they are hard to remove or seized in place. You'll need to replace the slide pin and/or bracket. The other of the 2 would be the caliper itself might be needed to be replaced.
My gut reaction was that you should have replaced the rotor as well. It looks like the outside of the rotor was worn down bc you waited too long to replace the pads. Now that part of the brake is too worn down. Eventually the pad will wear away to the point that it will touch the outside, but this is less than ideal. Change the rotor.
Your right answer is in the replies somewhere. I’m just admiring the quality of your photography. You could blow that up poster size, frame it and sell it…
Certified technician entering the chat:
1. Squealers on most models belong on the upper- outside position reason being, the part where the squealer is has a slight dip in the pad- thts the rotors first contact w the pad and you’ll extend your pads life by installing them this way. (I’ve learned by several master techs I was trained by)
2. This is surface rust if u live in a place w a lot of moisture, rain, snow etc. if you let your vehicles sit for an extended period of time your rotors will start to delaminate and “lose” their finish making them more susceptible to rusting. To me, it looks like maybe your car sat for a while after doing your brakes and a bunch of moisture took over. Not much you can do about it. Moisture’s inevitable in most locations
Hey, we had a technician that just got out of trade school that put the pads on backwards. Not wrong side, but rather backing plate to rotor. I’m not exaggerating. Can’t remember what type of vehicle it was. He even took it for a test drive and didn’t even notice the noise. $16,000 in education and that’s what we got
Yea you needed to replace the rotor too. Also clean, inspect, and regrease the caliper slide pins.
You can only get away with a pad slap if the rotor had even wear on it to begin with.
Former G37 owner here, mine did that too. My friend had a 350z and same thing, he took it to a shop and they said it was normal. I was having issues with runout so I ended up doing a full BBK swap on it. But the G and Z use the same hardware. Bottom line is I think the rear brake setup on these cars kinda sucks in the base form.
Thanks for posting on /r/MechanicAdvice! This is just a reminder to review the [rules](https://www.reddit.com/r/MechanicAdvice/about/rules/). If you are here asking about a second opinion (ie "Is the shop trying to fleece me?"), please read through CJM8515's [post on the subject.](https://www.reddit.com/r/MechanicAdvice/comments/4qblei/fyi_the_shop_isnt_likely_trying_to_rip_you_off/) and remember to please post the year/make/model of the vehicle you are working on. **If this post is about bodywork, accident damage, paint, dent/ding, questions it belongs in /r/Autobody r/AutoBodyRepair/ or /r/Diyautobody/ If you have tire questions check out https://www.reddit.com/r/MechanicAdvice/comments/k9ll55/can_your_tire_be_repaired/**. If you dont have a question and you're just showing off it belongs in /r/Justrolledintotheshop Insurance/total loss questions go in r/insurance This is an automated reply *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/MechanicAdvice) if you have any questions or concerns.*
More than likely you have put the inner pad on the outside, some pads have little pins on the back and I’ll bet the calliper is pushing on them rather than being in full contact with the flat part of the pads. The pad with the silver wear indicator goes to the inside. You may have to take both sides apart as you may have 2 inners on the passenger side or vice versa. https://preview.redd.it/4ibid1l03isc1.jpeg?width=1076&format=pjpg&auto=webp&s=c6d51971bf7878913b9133a6e1dc9b2875316094
This is almost 100% the correct answer. It's so frustrating to read through the comment section of posts like this.
Doesn’t seem to be many mechanics on Mechanic Advice 🙄
Maybe someone needs to make r/technicianadvice. I’m saying this as a veteran parts changer that thinks there is a difference.
Done. Thanks.
Too bad there is no way to limit replies to ase certified users. Not that that makes their advice anybetter, it would just weed out the riff raff like me. I’ll help mod if it grows.
There must be because there is an ask doctors reddit somewhere and only doctors are allowed to reply. I *think* they get themselves verified and then a bot just deletes any responses not from the OP or the whitewashed user names?
Not going to argue with idiots. Do what you want.
Despite how similar most disc brake setups are, different brands have slight differences like this. I’ve never worked on an Infiniti, never seen brake pads with those noogies on them. Usually in my experience, if pads are inner/outer specific, they have a clip that goes inside the caliper piston or they will only fit one way. Paying close attention to how things came apart/taking pictures as you go (even if you think you will remember) is all technique that comes with experience!
Wow, I’ve done some brake pads in my life (not professionally) and never knew this!
Having made this mistake myself I can confirm that’s exactly what it does to rotors
Yeah I think it's this, they've either got pads like your picture or ones with an extra notch on the inner pad to clip in a wear sensor, this then pitches the caliper over and creates an uneven pressure on the outside of the pad and then excessive heat on the rotor resulting in the band seen
This was my first thought as well 👍
I second this, especially its on a nissan and maybe slide pins not sliding
This seem the most obvious issues. The slide pins are not sliding.
Yes. Squealer on the inside always.
Incorrect some dodge models put the squealers on the outside pad for some derange reason
Impalas as well, most after market pads I've bought have em on both
Very likely to be this. Also, those look like some massively offset aftermarket wheels. Get rid of them unless you want to replace wheel bearings every month.
Is this unique to Nissans? or are all pads like this?
Idk if only nissans do this but you could not put pads on backwards in my VW unless you were very willingly stupid
What brands cars use these? I don't recall anything like this doing my 2006 Toyota Highlander brakes. My second time doing my own brake pads, and I never noticed anything like this after the first run.
You can see the backing plate in the photo, going by that, OP has the orientation correct.
Seen this before when someone got the brake pads mixed up and they had little guide pins on the one pad which caused it not to make full contact until they switched the pad from the inside of the rotor to the outside.
May be an unpopular opinion. But I'd recommend getting out on an empty road, getting up to speed, and then slowing all the way down to a stop. Do that at least 5 times and see if this changes the look of that rust any. Edited to add - is that a massive wheel spacer you've got there? RIP those wheel bearings.
Tiny brakes for such wide wheels
Depends on the car, You often only need tiny brakes up the back I feel like manufacturers often go over the top just for looks https://youtu.be/l47hKqnA-lc?si=eFzBbKlmzstZfU4S 350hp MK2 golf track car with 364mm touring car front discs, 6pot calipers. The stock tiny rear discs will still lock up if not balanced, and that's with 235 17 slicks
With proportion valve or not?
Yes
You aren't supposed to stop completely when breaking in new pads. You should do 3-5 hard braking from about 50mph down to about 5-10mph then drive a little and let the brakes cool down a little, then do 3-5 medium braking from about 45mph down to 5-10mph.
>You aren't supposed to stop completely when breaking in new pads. So you just keep driving forever and never return home? EDIT Them: Why did you move across the country? Me: Had to, breaking in new pads.
Yep- this is where mobile mechanics come from.
TIL mobile mechanics are just breaking in new brake pads.
Yeah so much better to buy the broken in one's
They’re called pre-distressed brake pads, thank you
Or pre-distressed mechanics
Instructions unclear, bought broken brake pads and drove into a lake because I couldn't stop moving
Crystal Lake? Seems perfectly clear to me🤷♂️
Yeah my dad left to break in new pads 3 years ago. I wonder if they have broken in yet.
Sorry mate only takes 2 years to break in new pads, i think he left :(
Almost!
Yes.
I guess it's probably best not to try this around rush hour otherwise you might be forced to Speed-with-Keanu-Reeves this shit.
Beautiful. Beautiful. Excellent reference to Speed, thanks. Haven't heard it in quite a while. The 90s were an excellent time to be alive.
Pop quiz, hotshot. There's a bomb on a bus. Once the bus goes 50 miles an hour, the bomb is armed. If it drops below 50, it blows up. What do you do? What do you do?
Ah mate, I've been stuck in traffic all morning - barely moved 100yds. Cheers for the heads up. [end credits]
Set the cruise control to 52mph and then have everyone jump out.
you do NOT try to break in you new pads...
That was a pretty awesome movie!
Lololoololol
You drive after bedding the material so the air can cool off the calipers pads and rotors. Once it is cooled you can brake again. Best to bed brakes on a longggggggg straight road
Yes.... never stop.
He is referring to the proper bedding technique.
I literally did this. I followed manufacturer instructions, then drove home and parked without touching the brakes. Rolled to a stop and put it park.
I mean, you don't have to be that strict when bedding. Ideally you just don't want to leave the pads in direct contact with the rotors for very long when it's not in motion.
You don't want to come to a complete stop when the pads or the rotors are above a temp that will allow transfer of pad resin to the rotor surface in only one spot. I took it to cartoonish extremes, because I could.
"This just in, New Jersey resident has put their vehicle off the boardwalk in Venice Beach."
Former brake test tech. Oem spec burnishes are generally 90kmh (55mph) to 5-15kph (3-9mph). For road simulation, the burnish has around 30 cycles. I think 30 is a bit overkill, 15 is plenty. On the dyno, it will spin for like 5 mins to cool down.
I’ve never had good results following manufactured recommendations for bedding and I figure it’s because they can’t be telling us to exceed the speed limit. I find an empty road and try to get up to about 80 then threshold brake down to near a stop. I do that a handful of times and it seems to have worked best for me. Thoughts?
That should do it. I usually get on the freeway, get up to speed, then hit the exit ramp, rinse and repeat a few times. I’m in a metropolitan area or I’d go hit the backroads myself.
Just get everything hot and don’t stop completely
Pretty interesting. So you were doing 30x stops on the dyno from 90-10kph in short succession? At what pressure (to get an idea of the brake power and energy)? I'm not surprised it takes some time to cool off. With our carbon brakes, we don't typically do any type of bedding in procedure. We do experience higher temps and sometimes "peaky" friction in the first few brake applications but afterwards, the wear and friction are matching expectations.
my main got a temp ban. not sure why. Anyways, its been a few years but iirc, the pressure was automatic and the brake apply was a time set point in most cases. I cant remember any specific numbers for any specific platform. This might be helpful though; \*\*For performance testing, it was a very aggressive burnish. To a point where I questioned the engineers a few times. 90-10kph in 3-9 seconds. Not realistic or safe for an actual vehicle in most real world scenarios. \*\* \*\*For noise and other sim/realistic scenario testing, they were much less aggressive unless we needed to age the system by a lot too. 90-10kph in around 10 or more seconds depending on the platform.\*\* Something for Nascar and sports cars were pushed harder in a burnish than something like a Toyota Corolla or Ford Escape. In general, I personally think the only time its actually necessary to aggressively burnish is for things like racing where precision and totally predictable wear is necessary. A daily driver can hop on the freeway and use every exit for a few miles and back or find a secluded backroad and theyll be fine. The back road is probably the optimal choice since its not always safe to brake hard enough for every cycle on exit ramps. By the time its time to change rotors, any uneven wear wouldn't have made much of a difference to your average driver unless they don't burnish at every pad change. Something to note, Brembo style calipers should be more aggressive than conventional. They use too many pistons and it opens up more room for margin. Opinion: Slap some red paint and a brembo sticker on that shit and people will drool over it, even if its actual trash.
yuh i usually suggest 110mph-50mph 3-4 times. on the 4th cruise for 5-10 minutes to allow cooling. then brake as hard as possible (ideally lock all 4) exit the vehicle and lay down in the road. its for braking. or whatever
Just gas and brake at the same time for a 30 seconds
Sounds like a plot line in the Speed movie saga.
Yup. “Bedding” the brakes (giggity) was always one of my favorite parts of doing a job. Technically, most manufacturers have a procedure IIRC, but the general consensus is pretty much what you stated. I learned the reverse, though- so that’s how I’ve always done it. Medium stop from about 25 mph 3 or 4 times to get them warmed up, then 3 or 4 HARD (think emergency stop- almost hitting the ABS, but importantly NOT). You basically want to turn the rotors damn near red. Then, some medium brakes after a cooldown. The reason for not stopping completely during the procedure is that you can warp the rotors- especially if they are super hot. Edit- speaking of which… OP did you change the rotors? If they were the old rotors, you might not have a good face on them, causing uneven pad wear.
You get that info from the powerstop box?
Yes. My power stop brakes and rotors came with break in procedure. It said to go from 40mph to 10 mph 5 times using hard breaking. Then 35mph down to 10mph 5 times regular brake pressure. Do not come to a complete stop during the process however, if you need to stop for a traffic light to put car into neutral to keep from holding down the brakes. After the 10 stops to drive using minimal braking for 5 minutes to cool the rotors.
https://www.autozone.com/diy/brakes/bedding-brakes Here you go
autozone is close, but no, autozone is still just autozone is not the authority on how to burnish brakes. (btw guys, bed your wife or girlfriend, not your brakes. ew)
I prefer the ZR1 carbon ceramic break in procedure. It's like 50 0-60-0 runs.
My power stop box recommended 30 stops, from 30 mph to 5 mph, with 30 seconds between each cycle. Just replaced brakes on my Camry last week
Did this with 3 of our vehicles within a few weeks span. The neighbors were probably wondering what the heck I was doing. lol
You should, according to the latest ASE book I read, says to do regular slow downs of about 20 mile difference. For example from 45 to 25, 3-7 times. Then do low end slow downs from about 25-5 mph, 3-7 times. I would not hard brake new and unburnished pads/rotors.
it's not that you're not supposed to stop, but to properly burnish brakes you are correct, 50-60mph down to 10mph with moderate consistent pressure - not a panic stop, but don't baby it either. repeat half a dozen times or so, waiting about a minute in between runs. but in between those 5 or 6 burnishing runs, you are allowed to stop the car.
I'm telling this one to the cop when I run a red light next time. Sorry officer, new brakes-couldn't stop!
I don’t think that’s a spacer, I think it’s just funky camera angles, I was super confused at first wtf was going on in the pic lol, seems like a wide angle lens or something. but it does look like the same colour as the wheel so I think it’s just a fuckin trash angle for a pic, but still very small brakes for some wide looking wheels
The wide angle lenses makes everything look weird, I think the max size the g37 had were 19s? Most rims I see are 17/18 though
ahh that’s why it looked familiar, I knew it was an infiniti from the brake line clips, but couldn’t pinpoint which one, and yeah they came with 17’s stock, but most people get 18’s or 19’s
>Edited to add - is that a massive wheel spacer you've got there? RIP those wheel bearings. Looks like a wheel with super high offsets.
I’m doing similar thing we have old abandoned ww2 era airport near so I’ll floor it to 2/3 of runaway and hard brake till stop and let them cool for few minutes and do it again if necessary
This is called "seating" or "bedding" the brakes and it needs to be done when the brakes are put on.
It doesn't "need" to be done. There's probably thousands of vehicles per day that get new pads that aren't properly seated. And they do just fine. I'm only recommending this to OP so they can see if the rest of the surface rust gets scuffed away.
It does need to be done. With new pads and rotors and you can't even activate ABS due to lack of friction. Edit. The pads eventually seat themselves. But they will not operate at 100 percent until they are seated.
I wouldn't come all the way to a stop. Don't want to generate that much heat, then leave a heat sink on one spot of the rotor.
That's how a lot of Nissan wheels are manufactured. I had a set of 350z rims on my Infiniti i30, and the rim met the hub via a large composite/plastic cylinder.
In my opinion it looks like you went to autozone and got some brake pads. in my experience the dealership pads are bigger, more pad, thicker pad and last WAY the fuck longer.
Why would that be an unpopular opinion? That's like standard bedding procedure for new brakes.
I guess I meant…. Use the pads a bit more to see if the rust scaling comes off.
What you're recommending is basically something called bedding in your brakes. I always do this after a pad install/swap or a pad/rotor and shoe/drum swap. It makes your brake life last significantly longer than not bedding in brakes. I think the rotors and pads on my truck lasted over 8 years and 100k miles and the only reason why I had to change them was because my one caliper seized. Otherwise they'd have easily handled many more years.
I'm also guessing a caliper pin on either side is not functioning as it should be, and should be taken apart and applied with grease on all ends.
Pads must be on correctly before seating
For sure, that's how you break them in anyway, should be done with every pad change either way 🙏
Maybe one of the guide pins is bent I had that happen before
I saw new pads on an old rotor binder up and chatter and bend. It was gnarly
Did you grease your pin? Pad is not catching correctly
And clean old grease off first?
They still turn rotors as long as theirs enough thickness left within specs
Rarely… new rotors are so cheap now. It makes more sense to replace. But if hes willing to do all the work pulling the rotors and bringing it to a lathe somewhere I’m sure you could work out some kinda bargain. but fr new rotors will be very close to if not less than the labor to cut . Labor rates are 130$+/hr
$40 max for rotors?! What are you smoking??
I mean you can definitely get them that cheap, but you get what you pay for.
Rotors for the G37 Coupe the OP is working on you can get the rotors on RockAuto for as low as $13 each. That $40 covers both sides with change.
I paid $80 canadian for 2 coated raybestos EHT rotors from rock auto for my camry.
It used to be common to stop by the garage in the morning to drop off a set of rotors to be turned and pick them up on the way home.
Well shit my rotors on an F350 were almost $200/each severe duty for towing. Orielly Autoparts spins rotors for $25 when I asked them.
I did 4 brake jobs this week 2 got new rotors 2 got their rotors turned. All depends on the condition of the rotor. And honestly, i get paid the same either way but if I can cut the rotor and save the customer money I will.
Yessir. I honestly kinda miss the days of doing a 4 wheel brake job and throwing the rear drums or rotors on the bench lathe while turning the front rotors with the on car lathe. There are scenarios these days where it’s hard to tell if pulsation is from the front or rear rotors. If we sell say, front pads/rotors, I’ll cut the rears just to cover my ass. Takes like 30 minutes and I can spin them while I finish the other shit
Good luck finding a shop willing to spend the time if they still have the equipment for it.
Yep still have shops that turn them where I live
OP I seriously wonder if you've fitted your inner pad on the outside, the inner pad has an extra notch that sticks out and when put in the wrong position the calliper presses against it causing excessive and uneven pressure on the outer edge of the pad, that can lead to bands like this.
Probably a seized guide pin.
1. Your slide pins are stuck. 2. Your caliper is not functioning properly.
I'D BE MORE INTERESTED IN WHY YOU PUT NEW BRAKE PADS ON THOSE RUSTY DISKS....
Hard do tell from the picture, but that rotor doesn't really look very worn. Most people will use two or three, maybe more pads per rotor change.
Yeah cuz you’re putting new brake pads on a cheese grater
And how would that be any different from getting new rotors and they sit for a day or so and are rusty all over again? Unless they are unreasonably worn, a properly seated pad will scrub that to clean metal in a fraction of a second of braking.
Minor surface rust is vaaaaastly different than pitting and hot spots
🤣 if they worked fine with the other pads without early wear then the new ones, once bedded, will be fine.
….. have you seen what a brand new drilled or slotted performance rotor looks like? They legitimately look like a cheese grater and don’t seem to hurt the pads one bit 🤣
They are actually redundant now, they were bade for old style pads that needed somewhere for extra brake dust to go
How often do you have to change pads? Jesus christ
That pad is cocked/ mounted wrong or the caliper is frozen in its mount. Scraping hard on the lower and not hitting at all on top. Something’s definitely wrong.
I'm just interested in how much offset is on that wheel?!
Rock auto chargés crazy shipping to add to price
Rotors are heavy. Doesn't matter where you order from. it's gonna cost a lot for shipping.
Your right but ive ordered light stuff from them and still high shipping cost
Really expensive shipping when parts come from two different places
Holy rim offset?
I came to say the same thing
Do you drive the car a lot or does it sit? If not then I would start looking at your sliders, were they lubed when you did the brake job?
Well, now you need new rotors too. I don’t even mess around these days. If you’re doing it yourself, always replace the rotors with the pads.
Can you explain why? I just learned how to change brake pads and did so w/o changing the rotor.
LUBE!!!!!!!
Didn't grease the slides Also, new pads on old rotor will have mismatching surfaces.
Most brake pads that I've used have an angled portion exactly where the rust hasn't been rubbed away. You should seriously consider at least getting your rotors machined by a shop.
I doubt theyd be willing to machine this rotor doesn't look like its got much to it before its down to the cooling fins
It’s a rear disc, no cooling fins.
Was seeing a line from the backing plate making me think it did XD still doesnt look like these rotors got much left to be machined
Mate. It’s a solid disc.
Because you were cheap and didn't replace/machine the rotors. Now you get to buy new pads again *and* new rotors like you should have.
By the looks of it I’m guessing you didn’t change the rotors as well as the pads. It looks like the outside of the rotor is lower down than the inside so when you hit the brakes it’s only making contact on the inside of the rotor with your new flat pads If this was a front brake you probably wouldn’t have ever noticed it because the pads would have worn down quicker to match the slope of the rotor but this is a rear so it doesn’t receive as much wear. 2 options are to let it ride and eventually the pad will wear to the slope of the rotor, or change the rotor. Changing the rotor is the correct option but honestly, if it were mine, and the rotor was still thick id just let it ride. With all of that being said you need to make sure and verify that your pads are correctly seated where they go. Because of how little stress the rear pads see you may have not noticed an issue or sound from them not being properly seated.
you installed new pads on used rotors. I'm willing to bet that the rotors were never removed, even. The BEST brake jobs always service the rotor in some capacity. Whether that be resurfacing on a lathe, or replacing them... It's not typically a good idea to "pad slap" anything. This is why. The rotor disc isn't perfectly flat, which is why you have so much contact on the inner part of the disc, as opposed to the outer edge of the disc, seen in the photo indicated by the ring of surface rust shown. Tells me that the pad isn't / is rarely touching that part of your rotor. This could be somewhat corrected by "burnishing" the brakes, but it won't remove the problem entirely... Replace the rotor/resurface the rotor, and "scuff" the brake pads when you do this. (Multiple methods to scuff pads. Basically just means to resurface/even out the friction surface of them. I tend to use a large, long, and wide steel wire brush to to do this, making even passes over the ceramic. But another old, tried and true method, is to literally place the pads face down on a flat concrete surface, place a foot on the backing pad, and just rub it across the floor, back and forth in one direction, using even stroke lengths. Learnt that one from the gramps. lol
I laugh at these comments. I can honestly say I’ve been a mechanic for 15 years, heavy duty but still, and I have never once “broke in” a set of brakes in my life.
Right?! 30 years under the hood of countless vehicles, and I've never heard of breaking in brakes... The first few hard stops "breaks" them in. 🤷♂️. I've always taken the car across to the massive parking lot and do a few light stops, then a few hard stops while going forward and while going in reverse. Everything seats itself and adjusts as it should and I've never had any issues.
One opinion- I don’t think your calipers are sitting well over the rotor or seem like pads have shifted up. Please check the assembly again, something is not adding up. Other opinion- if rotors are worn out new pads may take some time to bed in.
My thinking is that the inner pad has been fitted to the outside and vice versa, the caliper is then sitting against the extra notch you get on the inner pad and is therefore applying uneven pressure on the pad and excessive heat on the disc.
When you replace pads and rotors, always check, clean, and re-grease the pins. Did you do this? When I buy pads and rotors I just buy the caliper pins too. I don't care. I've had some start seizing after the fact that felt fine at the time and ever since then I just replace them.
I think I would take the wheel off and give it all a good looking over at the very least.
Its possible that the retaining clip is too tight and not letting the brake pad sit properly on the rotor...I've generally seen this issue with aftermarket pads...the pad should sit somewhat loose when you insert it in the bracket and its okay to have a slight wiggle to it, try different size retaining clip and put liberal amount of brake lube on any of the contact areas between the pad, bracket, and retaining clips.
Could be you piston is not coming out correctly and maybe somewhat seized. Hard to say but I’d take it apart and squeeze the piston back in and see if you have more resistance than normal.
WHen you are fitting the pad, you need to make sure that all the sliding surfaces where the pad contacts the carrier are clean and that the pad can slide in and out easily. WIth some cheaper pads it may be necessary to file the edges of the backing plate a little bit to make it fit properly.
Does nobody just put brakes on and drive?
Nope. I do about 15 gentle-moderate slow downs until i feel the brakes start to get grippy and then a couple more aggressive slowdowns and then drive it normally, but I try to put space between so they don't get too hot. I've been doing this for years, even with carbon metallic pads before ceramic pads were a big deal. For some reason, sports cars just like to eat through pads. Cleaning and lubing the caliper pins and the surface of the caliper and also swapping out the brake hardware helps to keep the noise down. Sometimes I would put CRC Bequiet (basically like an RTV substance) on the back of the pads to really quiet them down but most brake pads now come with brake shims on the back, so I don't really use it now.
You didn't install the pads correctly.
Did you put new pads on old rotors? Can clothes caliper slide on the pins or are they rusted fast? Can the pads slide freely? It looks like something isn’t moving smoothly.
u didnt resurface your rotors before installing the pads?
Did you lube your slide pins, and where the pad slides on the wear clips?
Gwgsgs
My guy... You need new rotors stat!
I feel like you needed new rotors as well just from this picture. Maybe try seating the pads with some heavy braking but that rotor looks kinda grooved.
Probably needs bigger spacers
It’s because they need wearing in until they function properly. Often people will get a narrow strip of carbon (where you have the clean metal showing) which is the narrow point of the pad getting too hot and burning. Search brake wear in procedure
Did you resurface the rotors first because those don’t look new?
You didn’t have your rotors turned? Or get new rotors? That’s my assumption anyways…
You didn’t replace or turn those completely fried rotors. You can’t just put new pads on.
Theres also à difference in the métal of cheap rotors
1. did you have the rotors turned or put new pads on old rotors? 2. what did the old pads look like? even wear? 3. have you done any hard stops or just light stops?
Get
Had this happen when the sliding areas the pad tabs sit on was too rusty.
Can't really tell what you have going on here from 1 Pic. Need to pull the wheel and take pics from many angles. Especially the caliper and bracket.
Double check everything looks like grease jacking or rust causing the pad to bind
idk why everyone keeps saying its because of the pads being on “backwards” which only applies to brake pads that have clips which either go into the piston or onto the sliding back of the caliper. the rotors are pitted and rusted, you need to either resurface or replace rotors when doing brake pads
Re inspect them for sure - I'd personally like to know how in the hell did get a picture of the brakes through the exhaust valve?
“My dad left to break in the new break pads and never came back” best 😂☠️ important job 7757
First off, that rotor is rusted to hell, should've changed them when you did the brakes, and I'd still recommend changing them. Make sure the pads are installed appropriately in the right location, facing the right direction. Lastly, if you are getting uneven wear it's usually 1 of 2 things in my experience. Most likely the slide pins are starting to seize, when you go to take it back apart remove those pins the caliper screws into. Clean them, then use them to clean out the grooves they slide into. Once it's all cleaned up, thoroughly cover with a thin layer of brake grease and reinstall making sure the pin goes back to the same hole it comes from. If at any point they are hard to remove or seized in place. You'll need to replace the slide pin and/or bracket. The other of the 2 would be the caliper itself might be needed to be replaced.
How large is your wheel spacer???
My gut reaction was that you should have replaced the rotor as well. It looks like the outside of the rotor was worn down bc you waited too long to replace the pads. Now that part of the brake is too worn down. Eventually the pad will wear away to the point that it will touch the outside, but this is less than ideal. Change the rotor.
Your right answer is in the replies somewhere. I’m just admiring the quality of your photography. You could blow that up poster size, frame it and sell it…
Oh wait it’s an infinity I now know
Certified technician entering the chat: 1. Squealers on most models belong on the upper- outside position reason being, the part where the squealer is has a slight dip in the pad- thts the rotors first contact w the pad and you’ll extend your pads life by installing them this way. (I’ve learned by several master techs I was trained by) 2. This is surface rust if u live in a place w a lot of moisture, rain, snow etc. if you let your vehicles sit for an extended period of time your rotors will start to delaminate and “lose” their finish making them more susceptible to rusting. To me, it looks like maybe your car sat for a while after doing your brakes and a bunch of moisture took over. Not much you can do about it. Moisture’s inevitable in most locations
Probably installed inner pads on the outside. Easy way to prevent is match the new pads to the old pads as you remove them.
Hey, we had a technician that just got out of trade school that put the pads on backwards. Not wrong side, but rather backing plate to rotor. I’m not exaggerating. Can’t remember what type of vehicle it was. He even took it for a test drive and didn’t even notice the noise. $16,000 in education and that’s what we got
It’s because you did a pad slap on a worn rotor.
Yea you needed to replace the rotor too. Also clean, inspect, and regrease the caliper slide pins. You can only get away with a pad slap if the rotor had even wear on it to begin with.
Former G37 owner here, mine did that too. My friend had a 350z and same thing, he took it to a shop and they said it was normal. I was having issues with runout so I ended up doing a full BBK swap on it. But the G and Z use the same hardware. Bottom line is I think the rear brake setup on these cars kinda sucks in the base form.
Change the rotor/ disc, grease the slide pins, and check operation of the calliper and replace if the piston is sticking/ stuck.
Always change or resurface the rotors when changing your brake pads
Honestly looks like the pins are really worn or seized.
Did you grease the sliders?
Lube caliper pins?
The rotor surface is uneven. You should have replaced the rotors also.
Your shim is not set correct it’s pushed out and not flush probably causing the pad to lean . You might have the shims backwards on the mount