[Evil Derboy]

I have a 2018 M5 with CCBs which has done around 43k miles. At a recent service the dealer states that discs and pads were 30% worn.

I’ve hunted across the internet across various sites but haven’t found an answer to my problem so posting up a thread in the hope that others might be able to give me some insight.

Many complain of brake squeal at low speeds in traffic and the accepted way to cure this is to take the car for a good run and get some heat into the brakes to re-bed them.

I have a different squeal issue. After moderate to heavy use my brakes squeal most noticeably when not being applied at all and when turning corners at speeds of up to 25mph. It is unbearable loud and is a constant squeak-squeak-squeak as the wheel turns.

This happens without my foot on the pedal at all. Visual inspection of the discs and pads don’t reveal any obvious concerns. Brakes work fine as well. The issue seems to kick in when the car is warm and after some use rather than first thing in the morning when it’s cold.

I’ve bought some anti-squeal paste that I was going to try but BMWs CCB brake service workshop procedure explicitly says not to use a product like this.

Has anyone experienced something similar? Any remedies outside of the usual advice about re-bedding the brakes etc (tried it. Doesn’t work).

[shawnhayes]

Having had race CCB's before, this happened to me after track days. It lasted until the transfer layer was worn off between track weekends.

If this is the same problem, you're not going to be able to make it go away.

Shawn

[Evil Derboy]

Originally Posted by shawnhayes

Having had race CCB's before, this happened to me after track days. It lasted until the transfer layer was worn off between track weekends.

If this is the same problem, you're not going to be able to make it go away.

Shawn

It hasnt done it at all today. I'm thinking that it may be the pads vibrating in the caliper assembly when cornering but I was fairly hard on the brakes today after work and it's not happened at all.

[pbonsalb]

How are the front wheel bearings?

[Evil Derboy]

Originally Posted by pbonsalb

How are the front wheel bearings?

It's definitely not wheel bearing noise.

[shawnhayes]

Originally Posted by Moonstone_UK

It's definitely not wheel bearing noise.

But its a fair question. We had a problem on early GT-R's in the states because the wheel bearings were not properly tightened. The result was that the brakes squeaked while turning because the wheel bearing wiggled "just enough" to make the pads squeal in the fixed caliper against the two piece rotor.

Later fix was to tighten the bearing to 140 ft/lbs to "seat" the bearing, and then loosen and retighten to 110 ft/lbs.

But the symptom was a funny squeal when turning.

Shawn

[pbonsalb]

Yes, my thought was not noise from front wheel bearings but play. On another car with aftermarket wheels and suspension, I developed a clearance issue to the wheel rim over time on one side that turned out to be a worn wheel bearing. They typically do not wear out evenly side to side so if you have brake noise on both sides when turning, it is less likely this is the answer. Sometimes just a mm or 2 of play can make a difference and slight wheel bearing play usually is evident only under load such as turning.

[Evil Derboy]

The brake squealing has disappeared of it's own accord. Haven't heard anything for weeks. Touch wood...