Brake noise (squeak) at very low speed

[JCL]

Originally Posted by scchang

Quick question: I have 50% left on my brakes according to trusted mechanic. Not sure if that refers to pads or rotors or both. I have had a low speed squeal as well which I attribute to aftermarket (low dust) pads. Rotors and pads were changed at the same time. Can I safely change just the pads to OE?

As long as the rotor is at least the minimum thickness, and the surface finish is reasonable, yes. The minimum thickness spec is stamped on the rotor. If they were changed recently, they are likely to be fine.

[Elvis 3.0]

I went to change my brake pads this past Sunday with my brother as I thought it was time. I had a hunch though the sensor wire didn't trigger the alarm. Anyway, it turns out that the sensor wire ( on the drivers side tire in the front) was not even attached. However, I looked at the pads and they were not even close to needing a change. Anyway, the upside was that I too was dealing with a low speed wheel squeal that was very noticeable rolling up to stop signs with the windows down. Being prepared to do the aforementioned expected brake job that never happened, I had 'anti-squeal' grease ready to apply to the calipers where they meet the break pad. I did not not even remove either the calipers or the pads and simply used a pinky finger dab of anti squeal at the extreme ends of the caliper (both north and south sides), and on both sides of those areas where the make contact with the pad. That is, the outer caliper where it faces you and where it touches the pad. I made an effort to get a tiny amount between the caliper and pad. Prior to application, I used a wire brush to remove excess rust off rotor, caliper, and anti rattle clip. I used anti-seize grease on the flat surface of the rotor hub and where the lugs enter the hub. The whole process took about 15 minutes per tire. Result- no squeal. Simple.

Hope that helps.

[scchang]

Originally Posted by JCL

As long as the rotor is at least the minimum thickness, and the surface finish is reasonable, yes. The minimum thickness spec is stamped on the rotor. If they were changed recently, they are likely to be fine.

Thanks. Now where the hell are my calipers...

[scchang]

Originally Posted by Elvis 3.0

I went to change my brake pads this past Sunday with my brother as I thought it was time. I had a hunch though the sensor wire didn't trigger the alarm. Anyway, it turns out that the sensor wire ( on the drivers side tire in the front) was not even attached. However, I looked at the pads and they were not even close to needing a change. Anyway, the upside was that I too was dealing with a low speed wheel squeal that was very noticeable rolling up to stop signs with the windows down. Being prepared to do the aforementioned expected brake job that never happened, I had 'anti-squeal' grease ready to apply to the calipers where they meet the break pad. I did not not even remove either the calipers or the pads and simply used a pinky finger dab of anti squeal at the extreme ends of the caliper (both north and south sides), and on both sides of those areas where the make contact with the pad. That is, the outer caliper where it faces you and where it touches the pad. I made an effort to get a tiny amount between the caliper and pad. Prior to application, I used a wire brush to remove excess rust off rotor, caliper, and anti rattle clip. I used anti-seize grease on the flat surface of the rotor hub and where the lugs enter the hub. The whole process took about 15 minutes per tire. Result- no squeal. Simple.

Hope that helps.

Thanks. What kind of anti-squeal/seize grease did you use?

[JCL]

Not sure about Elvis, but I use this:

http://www.permatex.com/products/Aut...ne_Formula.htm

Note that you want a high temperature caliper grease, not one of the plastic miracle gunk spreads that are intended to be put on the back of the pads.

[Elvis 3.0]

BMW Parts and BMW Accessories | Bavarian Autosport

it doesn't revert to a copyable link when you are on the site or I would have directed you to the specific item. After you put in the make and model, just type in 'brake' under search. I would recommend buying both the 1) anti-seize grease and 2) the noise free brake squeal silencer

I used the noise free on the pad itself where it comes into contact with the caliper. I used the anti seize on the flat part of the rotor hub as well as the lug areas of the rotor hub where the lugs are received. This is a very good idea for when you later remove the rotor as it is a rust inhibitor. Prior to doing all work, I used a $2 metal brush to remove rust from the rotor as well as the anti-rattle clips.


BavAuto is pretty good on the service and advice side if you need to call them, however in general their stuff is definitely more expensive I have found; however, their service guides/ videos/ newsletters/ and phone support are great, and therefore I will always buys simple maintenance items from them.

[staskaya]

Thanks Elvis for this suggestion....So with out taking the calipers you have applied noise canceller lubrication right? How did you do that and exactly where again did you apply this stuff.....I tried yesterday and didn't have any luck. Thanks..

[Elvis 3.0]

Ideally you would remove the entire pad (two per rotor) and apply to entire surface that will come into contact with rotor. The friction that occurs on this surface is typically where the squeal comes from in most instances.

In my case, since I ended up not doing brake job and replacing the pads, I applied only to the area that I could easily get to without removing them. That would be both the North and South points the brake pad as you look at it on the caliper, grabbing the rotor. My intention was to do a brake job that ended up not being necessary and fixing the existing squeal was an afterthought. ( I had a new set of Pagid pads that I ordered from BavAuto.com and had applied the anti-squeal 24 hours ahead of time, which is suggested, but not required. This would have prevented the future squeal in my case had I swapped out the pads and done a brake job).

Ideally, you would jack the X5 up and leave on jack stands, remove all 8 pads, apply anti-squeal to all 8 'outer' surfaces ( the surface that will actually be grabbed by the caliper), let stand for about an hour or so, and re-insert to each caliper. If this is done, you will most likely eliminate your brake squeal. You can call the techs at BavAuto on their 800 number. They are pretty helpful and all have done this to theirs BMW's, and can walk you through and other questions/ concerns. PS- it's nice day today in Boston so if you have the time today would be a good day outside. The actually labor involve would be 15 - 20 minutes per wheel after it is jacked up, to remove the pads; and about 5- 10 minutes per wheel to re-insert.
Hope that helps. Also, if your looking for 4 front Pagid pads with them already applied I'd be happy to cut you a deal- live in Boston.

[JCL]

There are two schools of thought on applying lubrication to the calipers and pads, and two different products that are typically used.

I put the high temperature grease previously mentioned on the 'ears' of the pads, highlighted in yellow. There are four spots on each wheel. Then I apply it to the caliper where those ears touch the caliper, also highlighted, four spots each wheel. To do this properly you need to undo the caliper (item 1) but not the caliper bracket, and lift the caliper up, to get better access.

Others may promote (either alone or in addition) the use of a plastic compound that is applied over the back of the pads, and which sets up. I don't like to use that except as a last resort. It can squeeze out over time (at which point the noise returns), and it can reduce the firmness of your brake pedal, since it is compressible.

As a side note, make sure that the anti-rattle clip that holds the pad in place is tight, and installed properly.

[staskaya]

Thanks so much for the details and the attachment JCL....I'll give this a shot this weekend.