[txm550i]

Looking for some help with the brakes on my 2018 M550i with the M Sport Brakes. Quick background, I'm a decent shade tree mechanic. I do as much of the maintenance on my cars as possible. I've done a lot of brake jobs but mostly on classic cars and trucks. This was my first time doing the brakes on a BMW.

I opted for OEM replacement equipment bought through FCP Euro. I ordered new rotors and pads for both the front and rear wheels. I bought Zimmerman rotors and ATE pads. Did the rear first and then about 2 weeks later did the front. I only had a warning for the rear brakes but decided to go ahead and do both the front and rear rather than wait for the front sensor to go off.

At each wheel I thoroughly washed and cleaned the calipers to remove as much brake dust and road grime as I could before re-assembling everything. Sprayed Brake Buster on each caliper and then just scrubbed them with a detailing brush and Adams car wash from a bucket. Nothing crazy.

For the rear I applied the brake grease recommended by FCP Euro (ATE Plastilube) on the hardware (only) after installing the hardware into the caliper bracket. For the front I did not apply brake grease to anything.

I am getting a bit of brake noise from the rear wheels but it only seems to happen when in reverse. For the moment I am planning to do them again and re-grease the hardware and back of the pads.

The front wheels however, are squealing really bad. Mostly during light braking but also even sometimes when hard braking. My questions are:

1) Are there specific recommended points to grease for both front and back? I don't have access to a service manual.

For the rear I will probably grease both sides of the hardware and also the back side of the pad where the piston makes contact. For the front, since there is no hardware AND the pads have a sticky backing on the backside of the pad already I am not sure where I would apply brake grease.

2) Are there other problems I should look for that are common on the G30 to cause brakes squealing? I did some research here and on Youtube etc... and I see ppl calling out the pads, the rotors, or either or, but I've installed everything new.

Any help would be appreciated!

Also on a side note, in case this may be the issue for the front brakes:

When I received the pads and wear sensor from FCP Euro, everything came in a new brown box. However, when I opened it, the actual product box inside that contained the pads was heavily damaged and the pads where just laying in the box in a pile. I've ordered replacement brake parts from FCP Euro now for both my wife's X4 and my M550i and each time the manufacturer packaging was in pretty bad shape but this was on a whole other level. Is this quality of packaging I should expect from FCP Euro? Is anyone else getting parts like this? Should I question these pads?

[txm550i]

Ngl, its been a minute since I've posted here but really surprised no one has responded. Post too long? No one else in the forum does their own brakes?

[maDjzo]

Is it possible that the initial pad layer hasn’t worn off/the pads haven’t fully bedded in? I was under the impression that until the pad settles in to the new rotor, vibrations are present especially going against the grain on reverse, causing squeaking? Maybe give it a bit more miles?

Then again I don’t know much about cars, nor do I do my own brakes.

[txm550i]

I've considered the possibility but that hasn't been my experience in the past. In an OEM application I don't think they should squeak at all. I did find a reference in the manuals available here in the forum that you're supposed to press the pedal and hold it for a full minute after installing new pads, which I did not do, but that's just to ensure the front pads achieve a good bond with the pistons in the front calipers.

Thanks for the reply though!! Appreciate it.

[TEF]

While not a certainty, the rear brakes on your vehicle use sliding calipers while the fronts are four-piston fixed calipers. When installing the rear pads, you mention the use of Plastilube on the pads, but did you also lubricate the guide pins used in the rear calipers? If these stick, the pads do not retract evenly and can sometimes remain in partial contact with the rotors.

[742002tii]

Thank you for taking the time to post this in detail.

While I do not have an answer for you, I hope other will take the time to read your post and reply.

My experience is identical in nearly every way. I tried installing, reinstalling after thoroughly cleaning and applying new and different products, lubing the back of the pads, adding adhesive to the back of the pads, etc. All things that were suggested to me to try. Nothing worked. The squealing was intolerable.

When nothing worked, I threw out the 'new' pads and purchased the same pads again *Hail Mary*. Leaving the new rotors installed and virtually untouched or tweaked. After installing the new pads, going through the break-in steps of 20 aggressive near-stops from a moderate speed while never allowing the wheels to come to a complete stop with the pads touching while the rotors were hot; the squealing was gone.

For about 3 months.

Now it's back.

But I'm glad it was gone for as long as it was.

I'm looking to formulate a plan and am taking suggestions to get them quiet again.

My packaging was also severely damaged. I imagine it is the nature of the contents though and not extreme mishandling. Very dense product with sharp edges (relative to size and weight) with insufficiently rated cardboard packaging. Nonetheless, it wasn't great finding my brake pads loose and upside-down in the box.

[Chappers 71]

Unfortunately it seems quite common for the m sport brakes to squeal under light braking.
I recently replaced the front pads with oem Brembo on my G31, & they squealed like a stuck pig. Stripped them down & re cleaned & added more Brembo B Quite brake grease & after the third time of doing so they are now mostly squeal free although they still do it on occasion, now I apply a little light left foot braking whilst still giving it a little throttle when they start to squeal & I’ve found this quickly cleans up the surfaces & the squealing stops.

I spoke to a tech at my local md & this is very common & was told they don’t have a permanent fix.
I suspect that I’ll be trying ceramic pads next time & will see if they are any better

[txm550i]

Update: After going back through the brakes again the squealing is completely gone but I have a theory as to why it may have happened that I will mention at the end.

Rear Brakes: I took them completely apart short of removing the mounting bracket and cleaned everything again: rotor, caliper, hardware and pads. After cleaning everything I installed the hardware back into the mounting bracket but before I installed them back I greased both the contact surface where the hardware comes into contact with the bracket AND the opposing contact surface that comes into contact with the pad. I also greased the back side of the pads.

Something to note here is that the pad facing the piston in the caliper will need grease in the center of the pad where the piston makes contact. The other pad is held in by the forked side of the caliper and thus the upper left and right corners of the pad and the sides of the pad need grease.

Front Brakes: Similar process to the above. Dis-assembled and cleaned everything: Rotor, caliper, pads, pins etc... Applied grease to the metal slides where the pad slides into the caliper only. I did not grease the back side of the pads given that for M Sport brakes, BMW requires that the pad bond to the pistons on each side via the bonding agent already applied to the pads when you buy them new.

Theory: As many of you are, I'm very particular about cleanliness on my cars. I own, restore and maintain a lot of classic cars and I just can't stand things to be greasy, dirty, or rusty. When I did the brakes the first time I was really disappointed to see what condition the center hub was in for each wheel. The small steel flange and inner portion of each of the hubs was greasy, dirty and very orange which was probably a combination of grease (applied by BMW) and rust.

Its just not in my nature to let that go, especially on my BMW. This sometimes gets me in trouble lol. So, I used a wire brush and cleaned everything as much as I could before installing the new rotor on each wheel.

Fast forward to round two and after taking each wheel off and inspecting the brake assembly on each wheel I noticed that the hubs were again very rusty and dirty. In fact, the hubs on the rear wheels had a lot of fresh new surface rust on them (flash rust) and I even noticed an orange string of color going around the inner side of the rims (imagine someone slinging paint on the wall with a brush).

So this time I cleaned each hub again with a wire brush, used a chemical I have that turns any existing rust into a black oxide and will prevent that area from flash rusting again and then applied some brake grease all around the outside of the flange and inside the inner portion of the hub.

My theory is that the brakes may not have been squealing initially after I finished the job but if the hubs got rusty again after I cleaned them and left them unprotected and then over time they started slinging rusty water all over the wheel and brake assembly that may have caused the squeaking.

I did notice that most of the pads were a bit orangey on the contact surface. Now it's been raining a lot here in Texas so that may have been a contributor but I wasn't going to take a chance.

So time will tell. If I didn't do a good job of stopping the rust, my brakes might start squealing again over time but I am hopeful the steps I took will be enough to prevent it from happening again.

I sincerely wish BMW would have used stainless steel for those hubs but I am sure that would be cost prohibitive.

This is certainly not a formal assertion from me that I found the problem but I drove the car and tested the brakes thoroughly in both forward and reverse and as of right now there is NO squealing. It if comes back, I'll update the thread.

[Alscoob]

Seems to be a common problem on most platforms, certainly the 3er & 4er models with blue calipers suffer with this.

Whether it's true or not, recents post over there have suspected that it's the use of non BMW pads that cause the issue. While BMW pads are made by a major pad manufacturer the OEM versions same manufacturer produced are not the same as those for the BMW spec. Perhaps a little more tollerance or differing pad material allow movement thus the squeal.

I recall changing the pads and rotas on my 330d F31, added Textar grooved and dimpled two piece ones (same as M Performance) and OEM spec Pagid pads, not only did they squeal at crawling pace in traffic with light pedal pressure when hot but if you stopped then reversed and braked, you would hear the front pads 'clunk' as they moved in the caliper.

I got used to that, although frustrating, and when they started to squeal did some firm braking which stopped it for a good while, but ultimately was a pain in the butt.

My last 340i F31 was on original pads and rotas when I sold it at 72K miles and quiet as a mouse in it's life with me. Still plenty of pad left and rotas okay, so guess that original BMW products cost more but do last, but I also do read the road and am not one of those on / off - on / off brake characters you follow. On one occasion on an 18 mile run through some twisty roads I braked once and that was at a 'Halt' junction, the car we followed braked 43 times, hard to believe and clearly no confidence.

[Alscoob]

Originally Posted by txm550i

When I received the pads and wear sensor from FCP Euro, everything came in a new brown box. However, when I opened it, the actual product box inside that contained the pads was heavily damaged and the pads where just laying in the box in a pile. I've ordered replacement brake parts from FCP Euro now for both my wife's X4 and my M550i and each time the manufacturer packaging was in pretty bad shape but this was on a whole other level. Is this quality of packaging I should expect from FCP Euro? Is anyone else getting parts like this? Should I question these pads?

Blimey... thats bad I would have insisted they be replaces as who knows what danage could have been done with them bouncing around in a box together.

I ordered some pads a while ago, the turned up boxed but also in another bigger box with sod all packing and looked like they had been thrown around some damage to the inner box but worst bit that the top part of one pad had snapped off. Had they been more packaging in the bigger box I guess all would have been fine.





They were changed by the supplier without question on a next day delivery, but it does show how fragile these things can be.

[txm550i]

Update: Initially I had no squealing but within just a couple of days it came back. It only happens at very low speed braking but its very loud and very persistent. Took the car in for service today for a number of other items and asked them to look at it. It went about as well as you'd expect.

Initial response was to mention the existing bulletin from BMW and the fact that M-Sport brakes are prone to squealing. I asked them to look at it anyway and the Technician opted to recommend a procedure to me to chamfer the pads and apply an anti-squeal paste to the surface of the pads (very odd suggestion to me, typically you do not ever want anything on the surface of the pad or the rotor) at a cost of $611 for both axles (also odd given the rear brakes were not making any noise). I spoke about it to my Service Advisor and he mentioned that their Service Manager and he both had concerns about making even that recommendation because, as I chose to use aftermarket parts from FCP Euro, it was impossible for them to determine if the problem might be the pads or even the rotors. I opted out of the procedure and will just have to try and tackle the problem myself. I might try and different set of pads next though based on other posts I've read, including recent ones here there's no guarantee that will fix the issue.

My recommendation to others considering doing the brakes themselves at this point, barring whatever additional success or failure I might have as I continue to try and eliminate the issue is to buy and install BMW rotors and pads. If I had it to do over again I would go that route first. For reference the dealer quoted me ~$2800 for the brake job in early-2023 when I had it in for another minor service. A similar quote might be much more now given inflation, increases in labor and parts cost etc... Doing it myself with parts from FPC Euro I spent about a $1000 total in parts for both axles so I saved a significant amount on the labor etc... but now I have squeaky brakes.

Ironically, those of you that opt to have the dealer do it, using BMW parts, may still run into the same issue if your also running M-Sport Brakes. Keep in mind they have the official bulletin from BMW they can point to as a get out of jail free card.

[txm550i]

Originally Posted by Alscoob

Seems to be a common problem on most platforms, certainly the 3er & 4er models with blue calipers suffer with this.

Whether it's true or not, recents post over there have suspected that it's the use of non BMW pads that cause the issue. While BMW pads are made by a major pad manufacturer the OEM versions same manufacturer produced are not the same as those for the BMW spec. Perhaps a little more tollerance or differing pad material allow movement thus the squeal.

I recall changing the pads and rotas on my 330d F31, added Textar grooved and dimpled two piece ones (same as M Performance) and OEM spec Pagid pads, not only did they squeal at crawling pace in traffic with light pedal pressure when hot but if you stopped then reversed and braked, you would hear the front pads 'clunk' as they moved in the caliper.

I got used to that, although frustrating, and when they started to squeal did some firm braking which stopped it for a good while, but ultimately was a pain in the butt.

My last 340i F31 was on original pads and rotas when I sold it at 72K miles and quiet as a mouse in it's life with me. Still plenty of pad left and rotas okay, so guess that original BMW products cost more but do last, but I also do read the road and am not one of those on / off - on / off brake characters you follow. On one occasion on an 18 mile run through some twisty roads I braked once and that was at a 'Halt' junction, the car we followed braked 43 times, hard to believe and clearly no confidence.

Thank you for the feedback. This is effectively what my local dealer stated as well. Using non-BMW parts means everything is in question, both the pads and the rotors. Thankfully (knock on wood) I have no clunking (I think that would be worse) but the squealing is awful, and embarrassing.

[txm550i]

Originally Posted by Alscoob

Attachment 3381629

Blimey... thats bad I would have insisted they be replaces as who knows what danage could have been done with them bouncing around in a box together.

I ordered some pads a while ago, the turned up boxed but also in another bigger box with sod all packing and looked like they had been thrown around some damage to the inner box but worst bit that the top part of one pad had snapped off. Had they been more packaging in the bigger box I guess all would have been fine.

They were changed by the supplier without question on a next day delivery, but it does show how fragile these things can be.

That's terrible. Seems like this may be an issue across the industry and not just unique to FCP Euro. I think its a by-product of the "Order everything on Amazon" era we live in now where so much of what we buy is packaged and shipped to our door. Ppl don't buy things in-store as often anymore and I think overall quality of shipping standards have dropped across the board. Its that same mentality for petty theft - no big deal if the shipment gets damaged, the retailer will send it again or the carrier will replace it etc....

[tjbuggy2b]

Not sure if it will make much difference but have you tried using the type of antisqueel that is sort of like RTV, where it cures into a sort of rubbery coating on the back of the pad? Don't put it on the area that is meant to bond with the pistons but maybe that instead of the plastilube? Maybe a different type of antisqueel could make a difference?

Did you replace the guide pins on the fronts? BMW lists them as "refresh". I know mine were pretty well beat up and I am replacing them when I do my brakes this weekend.

I'm doing Brakenetic slotted rotors with Powerstop NextGen Euro carbon-ceramic pads. Hoping I don't run into the same issue.

Speaking of rotors, did you check the wear pattern on yours? Mine are pretty heavily grooved after ~60k miles, which is why I'm replacing them.