[captain slowly]

So my car is getting the front brakes replaced under warranty for the second time in 20000 miles, with the last set only lasting 1800 miles before getting "warped". Seems this is a wide spread issue with the 2NH brakes, and particularly the pads BMW uses. So I'm thinking, when I pick up the car from the dealer later today, I should replace the pads pretty much immediately to save the rotors. Is there a good pad that doesn't dust as much as the stock ones and has decent bite? The car isn't tracked so I don't need anything super fancy.

Thanks.

[MooMooM2]

this is strange as modern rotors don't really warp easily and specially with 1800 miles. This is probably pad deposits from the stock pads (also strange since you don't track). I am surprised they just been replacing your rotors. But yeah Id put different pads on there that are not known to easily leave deposits, I forget now but there is a low dust pad that everyone loves here.

[captain slowly]

Originally Posted by MooMooM2

this is strange as modern rotors don't really warp easily and specially with 1800 miles. This is probably pad deposits from the stock pads (also strange since you don't track). I am surprised they just been replacing your rotors. But yeah Id put different pads on there that are not known to easily leave deposits, I forget now but there is a low dust pad that everyone loves here.

That's what I'm thinking, it's gotta be the pads they use. I'm toying with selling the car so it might be a non issue, but if I do keep it I need to address this as I'm getting tired of dealing with this.

[Apexeater]

Carbotech 1521. great for street, little dust, no noise. no track though

[Maynard]

I think you might be good to take it to a good indie shop to look it over. As MooMoo noted, most likely is pad deposit or incomplete bedding in, not real warpage. True warping is pretty rare, and almost always the result of something causing uneven rub/heat; common culprit is a pad on one side stuck out so it stays on the disc, while the other side retracts. It can also be from miniscule imperfections that leave the disc not exactly true to the axis of rotation. Another option could be that you don't heat things up enough to loosen up the disc pins and they get corroded in place. Either way, if the dealer is just throwing pads and rotors at it they aren't addressing it. Factory M pads are not the typical low-buck oem junk, so I doubt they are the problem - but if they are, then it is pad deposits not warpage.

[///MPhatic]

Originally Posted by captain slowly

So my car is getting the front brakes replaced under warranty for the second time in 20000 miles, with the last set only lasting 1800 miles before getting "warped". Seems this is a wide spread issue with the 2NH brakes, and particularly the pads BMW uses. So I'm thinking, when I pick up the car from the dealer later today, I should replace the pads pretty much immediately to save the rotors. Is there a good pad that doesn't dust as much as the stock ones and has decent bite? The car isn't tracked so I don't need anything super fancy.

Thanks.

1. Modern brake rotors do not warp unless you run off the track into a cold lake.
2. What's happening is that the OE pad used by BMW actually needs to be bedded in, and done in a very specific way, otherwise the pad deposits on the rotor get uneven and cause pulsation.
3. CarboTech 1521 is the best street pad on the planet for the 2NH with no noise, vastly less dust, and they'll double the life of your rotors (make sure to use the OE rear pad shim, but not the front). The 1521 is perfectly happy in the canyons as well, but they are not meant for HPED or track use.
4. The stock pad is progressive, meaning the more heat they get in them the harder they bite, even if you don't add pedal. The 1521 is linear, meaning they stop much more evenly. Linear pads are preferred by most.
5. Initial bite with the 1521 is good, as is rain performance.
6. The 1521 does not need bedding in, just 300 easy street miles.

[chris719]

Originally Posted by ///MPhatic

5. Initial bite with the 1521 is good, as is rain performance.

The 1521 was absolutely terrifying for me in the rain if it was heavy enough to really soak the wheel well. It was only a problem when it was cold and there was a ton of water on the roads, but it was really bad (seconds with zero bite) and it's hard to describe how bad it was and also the strange groaning / "stiction" type vibration you would get trying to activate ABS as a test in conditions where the water film was built up. I could reproduce it with a pressure washer as well. I never got a chance to drive them in warmer weather to see if it was a problem, but I was going to get rid of the pads in the spring.

Other than this behavior, it was fine.

[///MPhatic]

Originally Posted by chris719

The 1521 was absolutely terrifying for me in the rain if it was heavy enough to really soak the wheel well. It was only a problem when it was cold and there was a ton of water on the roads, but it was really bad (seconds with zero bite) and it's hard to describe how bad it was and also the strange groaning / "stiction" type vibration you would get trying to activate ABS as a test in conditions where the water film was built up. I could reproduce it with a pressure washer as well. I never got a chance to drive them in warmer weather to see if it was a problem, but I was going to get rid of the pads in the spring.

Other than this behavior, it was fine.

That's very interesting, and something I never experienced or have heard of. Maybe I just don't drive in heavy enough rain.

Having said this, no matter what you do, don't go CCB, they're vastly worse in wet conditions.

[captain slowly]

Originally Posted by ///MPhatic

1. Modern brake rotors do not warp unless you run off the track into a cold lake.
2. What's happening is that the OE pad used by BMW actually needs to be bedded in, and done in a very specific way, otherwise the pad deposits on the rotor get uneven and cause pulsation.
3. CarboTech 1521 is the best street pad on the planet for the 2NH with no noise, vastly less dust, and they'll double the life of your rotors (make sure to use the OE rear pad shim, but not the front). The 1521 is perfectly happy in the canyons as well, but they are not meant for HPED or track use.
4. The stock pad is progressive, meaning the more heat they get in them the harder they bite, even if you don't add pedal. The 1521 is linear, meaning they stop much more evenly. Linear pads are preferred by most.
5. Initial bite with the 1521 is good, as is rain performance.
6. The 1521 does not need bedding in, just 300 easy street miles.

Question on #2. How do I bed these in so it doesn't happen again? I know the "normal" way, but not sure about the "specific" way. Also, I was told by my SA that the pads I'll be getting today have been updated, but I'll compare part numbers from last time to be sure.

[captain slowly]

Originally Posted by Maynard

I think you might be good to take it to a good indie shop to look it over. As MooMoo noted, most likely is pad deposit or incomplete bedding in, not real warpage. True warping is pretty rare, and almost always the result of something causing uneven rub/heat; common culprit is a pad on one side stuck out so it stays on the disc, while the other side retracts. It can also be from miniscule imperfections that leave the disc not exactly true to the axis of rotation. Another option could be that you don't heat things up enough to loosen up the disc pins and they get corroded in place. Either way, if the dealer is just throwing pads and rotors at it they aren't addressing it. Factory M pads are not the typical low-buck oem junk, so I doubt they are the problem - but if they are, then it is pad deposits not warpage.

I don't disagree that it's pad deposits instead of warpage, perhaps I used the wrong term. As long as the car is under warranty, I'll make BMW replace as many pads/rotors as it takes, which is another year, but at one point I'd like to address the issue. I was thinking Girodisk rotors and Pagid RSL29 or the Carbotechs that were suggested. IDK

[///MPhatic]

Originally Posted by captain slowly

Question on #2. How do I bed these in so it doesn't happen again? I know the "normal" way, but not sure about the "specific" way. Also, I was told by my SA that the pads I'll be getting today have been updated, but I'll compare part numbers from last time to be sure.

IIRC the bedding in process for the stock pads is a version of the standard procedure, but not as aggressive, although I have no faith in that because a.) BMW doesn't advise you to do so (even though they have replaced thousands of rotors because of the deposits since their policy isn't to turn them because they only have 1.4mm of available wear), and b.) because I haven't heard of anyone that had great success with it.

I would advise you don't bed/use them at all. Park the car or drive it normally until you get your new pads.

Lastly, I don't believe they changed the pad enough to make a difference, as it isn't in their interest to do so.

Originally Posted by captain slowly

I don't disagree that it's pad deposits instead of warpage, perhaps I used the wrong term. As long as the car is under warranty, I'll make BMW replace as many pads/rotors as it takes, which is another year, but at one point I'd like to address the issue. I was thinking Girodisk rotors and Pagid RSL29 or the Carbotechs that were suggested. IDK

The only problem with this is if you don't have issues that BMW can replicate a year from now then you're stuck with those rotors, the brake dust, the wear, etc. Better to fix it properly IMO, but to each their own.

[MooMooM2]

Id leave the discs, unless you were tracking the car and wanted a 2 piece the stock discs are more than find (they are fine on track too), just replace the pads. Pagid is hate it or love it, some love em others hate em so ymmv

[captain slowly]

Originally Posted by ///MPhatic

IIRC the bedding in process for the stock pads is a version of the standard procedure, but not as aggressive, although I have no faith in that because a.) BMW doesn't advise you to do so (even though they have replaced thousands of rotors because of the deposits since their policy isn't to turn them because they only have 1.4mm of available wear), and b.) because I haven't heard of anyone that had great success with it.

I would advise you don't bed/use them at all. Park the car or drive it normally until you get your new pads.

Lastly, I don't believe they changed the pad enough to make a difference, as it isn't in their interest to do so.



The only problem with this is if you don't have issues that BMW can replicate a year from now then you're stuck with those rotors, the brake dust, the wear, etc. Better to fix it properly IMO, but to each their own.

I would think that since they're replacing pads/rotors constantly, they'd want to improve the pads so they don't have to pay anymore, but logic isn't always my friend. Either way, we'll see later.

[captain slowly]

Originally Posted by MooMooM2

Id leave the discs, unless you were tracking the car and wanted a 2 piece the stock discs are more than find (they are fine on track too), just replace the pads. Pagid is hate it or love it, some love em others hate em so ymmv

I meant if the stock ones had pad deposits and needed to be replaced anyway, I'd spring up for the Girodisk as they are lighter, and as childish as it sounds, look badass.

[captain slowly]

also, ECS tuning has stop tech and EBC pads. Does anyone know anything about either?

[///MPhatic]

Originally Posted by captain slowly

I would think that since they're replacing pads/rotors constantly, they'd want to improve the pads so they don't have to pay anymore.

I hope you're right, I just have no faith in them to do so, even when it seems reasonable to us.

[chris719]

Originally Posted by captain slowly

also, ECS tuning has stop tech and EBC pads. Does anyone know anything about either?

EBC Redstuff might be a decent choice as well. Never tried Stoptech. I was personally going to try Endless MX72 Plus but they aren't low dust.

[chris719]

Originally Posted by captain slowly

I would think that since they're replacing pads/rotors constantly, they'd want to improve the pads so they don't have to pay anymore, but logic isn't always my friend. Either way, we'll see later.

This pad material is a type of NAO. They had to change from the older semi metal formulation to meet Euro 6 or some other EU/ECE requirement a while back. I don't think this is an ideal pad as far as engineering alone is concerned.

[captain slowly]

so bmw did change the part number. Last time they replaced my brakes in October, they used part number 34-11-2-284-869. Today they used 34-11-9-502-904. From googling I can't tell what the actual difference in pad material is, but it's definitely a different pad.

[///MPhatic]

Originally Posted by captain slowly

so bmw did change the part number. Last time they replaced my brakes in October, they used part number 34-11-2-284-869. Today they used 34-11-9-502-904. From googling I can't tell what the actual difference in pad material is, but it's definitely a different pad.

But I'll bet the goal of the pad is the same; to cause deposits and eat your rotors prematurely.

[chris719]

Originally Posted by captain slowly

so bmw did change the part number. Last time they replaced my brakes in October, they used part number 34-11-2-284-869. Today they used 34-11-9-502-904. From googling I can't tell what the actual difference in pad material is, but it's definitely a different pad.

I should check mine that I pulled off my 2021 car. I noticed that the weights on my pad were black not stainless like most videos show. The pad was also mfg by Pagid not Textar, but it's just a second source of the same material as far as I can tell.

[captain slowly]

Originally Posted by ///MPhatic

But I'll bet the goal of the pad is the same; to cause deposits and eat your rotors prematurely.

I have no doubt