Another front brake squealing thread (1 Viewer)

[NorCalFJ100]

I have about 25k miles on brand new OEM pads and rotors.

I've pulled the pads and re-greased all the metal to metal contact areas of the shims and anti rattle stuff.

I put brand new slid pins in and used the dremel to lightly clean out the slid pin holes.

I've cleaned everything with brake cleaner and my air hose.

Brakes STILL squeal. It's more intense when it's cold and just gets moving, but for sure still there even once the brake system warms up.

It's only once I'm at a slow speed...like the last 20-30' before I come to a stop. But it's loud.

Brakes pads still have probably 50% life. I'm a very calm stopper. Lol. I very rarely ever even need to stop hard. The brakes on these newer 100s have amazing stopping power.

Do you think some how the pads got glazed over?? They didn't look bad when I pulled them to inspect, but I'm not an expert at spotting glazed pads.

I'm out of ideas...the noise is pretty annoying.

 

[Ayune]

After replacing my front pads & rotors I was having an annoying scraping when my brakes were cold. I found that the pad surface was too large and contacting the non-machined portion of the rotor near the hub. You can see the small area on the pics below. All OEM parts too, these particular examples just weren’t compatible with each other. Check to see if you have similar wear marks on your pads.

I replaced the pads with Akebono ACT772 and the issue went away. The pad area is slightly smaller near the hub.

Amazon product ASIN B000C1LLIW

 

[AlpineAccess]

Confirming that you said you put in anti rattle stuff - did you install a shim kit on the brakes? Did you apply silicone brake goop to the back of the pads?

I had noise until I got the shim kit in properly and installed the pads with the anti-squeal brake silicone on the back. Quiet now, with the occasional 2-3 second squeak on very cold mornings.

 

[NorCalFJ100]

After replacing my front pads & rotors I was having an annoying scraping when my brakes were cold. I found that the pad surface was too large and contacting the non-machined portion of the rotor near the hub. You can see the small area on the pics below. All OEM parts too, these particular examples just weren’t compatible with each other. Check to see if you have similar wear marks on your pads.

I replaced the pads with Akebono ACT772 and the issue went away. The pad area is slightly smaller near the hub.
View attachment 2522626
Amazon product ASIN B000C1LLIW

I'll double check. That is pretty crazy tho there would be that type of wear with oem stuff. Thank you for the tip.

Confirming that you said you put in anti rattle stuff - did you install a shim kit on the brakes? Did you apply silicone brake goop to the back of the pads?

I had noise until I got the shim kit in properly and installed the pads with the anti-squeal brake silicone on the back. Quiet now, with the occasional 2-3 second squeak on very cold mornings.

I did install the shim and anti rattle stuff. I applied grease as well...I replaced all that stuff when I did my brakes, but upon my last troubleshooting session I took all that stuff apart, cleaned it and re-greased it.

 

[vipergrhd]

Is your rotor surface glazed?

 

[NorCalFJ100]

Is your rotor surface glazed?

They don't look glazed...but I could be wrong. Anything particular I should look for?

What causes them to glaze most of time?

 

[vipergrhd]

They don't look glazed...but I could be wrong. Anything particular I should look for?

What causes them to glaze most of time?

It's almost like mirror finish, really smooth like polished surface. Get a green Roloc disc and angle die grinder to rough up the surface.

 

[NorCalFJ100]

How does this look?

 

[AlpineAccess]

I'll double check. That is pretty crazy tho there would be that type of wear with oem stuff. Thank you for the tip.



I did install the shim and anti rattle stuff. I applied grease as well...I replaced all that stuff when I did my brakes, but upon my last troubleshooting session I took all that stuff apart, cleaned it and re-greased it.

The stuff I'm mentioning isnt grease, it's the silicone stuff that goes on the back of the pad in between the shims and the pad. The bottle I have is called CRC Disc Brake Quiet.

 

[NorCalFJ100]

The stuff I'm mentioning isnt grease, it's the silicone stuff that goes on the back of the pad in between the shims and the pad. The bottle I have is called CRC Disc Brake Quiet.

That is correct. I should have been more specific, but that is what I used.

 

[NorCalFJ100]

Well....I was reading on another forum about how "babying" the brakes or lots of slow speed frequent braking aka lots of Los Angeles traffic, can actually be bad for brakes. Someone mentioned essentially bedding the brakes again. I just took it for a spin and heated up those brakes in 6 hard braking sessions and squeal seems to be gone!!!

Will report back after some more driving next few days. But hopefully this is it and helps someone else!

 

[2001LC]

I recommend power washing pads & calipers often along with undercarriage. After washing drive and brake to dry. I recommend this for everyone on all brakes. It's one of those areas many ignore or fear getting wet. This is even more import if driving off road, dusty condition, mud, salt & sand roads, water crossing, etc.

If squeal, with good pads (>3mm), then re-bed as first step.

 

[NorCalFJ100]

I recommend power washing pads & calipers often along with undercarriage. After washing drive and brake to dry. I recommend this for everyone on all brakes. It's one of those areas many ignore or fear getting wet. This is even more import if driving off road, dusty condition, mud, salt & sand roads, water crossing, etc.

If squeal, with good pads (>3mm), then re-bed as first step.

Good advice! Thank you!

 

[NorCalFJ100]

I'd say majority of my noise is gone...the re-bedding process seemed to help. But then all of a sudden it came back. I bed them again a few times. Seemed to have gone.

Being that this is obviously a glazed rotor/pad issue...perhaps I need to take @vipergrhd advice. I assume I need to rough up both sides of the rotor? Should I do anything with the pads?

Would the official solution to glazed rotors/pads be to turn the rotors and replace the pads prematurely?

 

[vipergrhd]

View attachment 2522883
How does this look?

Rotor is glazed sir. You need to scuff the pads surface too just to rid of the glaze.

One of the shop i use to work for use this on brake noise issue it seems to work most of the time.

Bottle of BMW Approved! BG #860 Brake Stop Squeal... | eBay

As part of the BG Stop Squeal® Service, BG Stop Squeal® is a safe and effective product for eliminating or preventing brake noise by infusing the brake pad with ingredients that reduce sticking between the pad and rotor.

www.ebay.com

 

[NorCalFJ100]

Rotor is glazed sir. You need to scuff the pads surface too just to rid of the glaze.

It's crazy because this 100 is my daily driver. Bone stock. I drive it very nicely. No dirt. Always clean...BUT I live in the concrete jungle of Los Angeles and I sit in a good amount of traffic. I had no idea that attributed to glazed rotors.

Do you think I'm better of turning the rotors and new pads? Or is your suggestion really pretty straightforward and will work long term?

I'm guessing I just use the angle grinder just long enough to get rid of the sheen, right?

Thank you!!

 

[vipergrhd]

It's crazy because this 100 is my daily driver. Bone stock. I drive it very nicely. No dirt. Always clean...BUT I live in the concrete jungle of Los Angeles and I sit in a good amount of traffic. I had no idea that attributed to glazed rotors.

Do you think I'm better of turning the rotors and new pads? Or is your suggestion really pretty straightforward and will work long term?

I'm guessing I just use the angle grinder just long enough to get rid of the sheen, right?

Thank you!!

Even if you cut the rotors and put new pads but still brake the same you might be back to your original issue. Labor is cheap and give the scuffing a try and see what happens. Try criscross the pattern on the rotor it helps giving the pad to bite on when you bed the pads again.

 

[NorCalFJ100]

Even if you cut the rotors and put new pads but still brake the same you might be back to your original issue. Labor is cheap and give the scuffing a try and see what happens. Try criscross the pattern on the rotor it helps giving the pad to bite on when you bed the pads again.

Thank you!! I definitely think I'll try more hard braking occasionally in the future! Haha.

I'll see how this week goes and maybe give your solution a try if it comes back with a vengeance.

 

[NorCalFJ100]

Well....the squeaking is back. Really it didn't stay away very long. I've just been driving my 80 a bunch lately.

I was thinking about scuffing up the rotors and pads. But I have an extra set of old rotors. I was going to take them down to the shop and see if I can get them turned.

You all think the very best surefire fix is to throw on some newly turned rotors and a new set of pads?

 

[2001LC]

A few suggestions:
Make sure hub to rotor surface clean and flat. "Flat" Sometimes guys hammer on hub with steel, wrapping matting surface. I hammer and file to flatten back out.
When you assemble, make sure to set wheel bearing breakaway preload to the upper limit.
Check disk run out.
Flat sand your old pads, or better yet replace them.
Get some pictures of assembly as you go. Post here.
Bed-in at over 35MPH and do not come to a stop with foot brake held down, until rotors & pads cool.