new brakes but annoying squeal, help!

[TurboLove]

so I just had complete pads, rotors and sensors- front & rear- replaced on my 08 CTT (44K miles). The brake sensor light had gone on and I had been driving with some major squeaky brakes for a looooong time (probably 1.5 years+) So I am thinking, boy, I cant wait to get new brakes and get rid of the squeaking.

However, here I am posting this (after doing a forum search)- 500 miles after new brakes installed- crying about font brake squealing. The squealing occurs just when I come to a complete stop; just as I go from 5mph to stop. And its not a simple squeal. Its loud (and it sounds different from my squeaking brakes before the job was done.) I actually get embarrased when I am in traffic. So here's my question: before I drive back to my indie shop who did the work, what do I need to consider? is it the pads? rotors? what is the culprit? the repair guy did tell me that squeaky brakes may not be completely silenced after the brake job but this is ridiculous....I'm at my wits end right now. I could use some solid advice.

[kbrandsma]

You have a couple of choices. You can change the pads which is most likely the culprit or you can coat the back face of the pad's backing plates with high-temp brake grease or brake anti-seize compound. Some use teflon shims.

[JFP in PA]

so I just had complete pads, rotors and sensors- front & rear- replaced on my 08 CTT (44K miles). The brake sensor light had gone on and I had been driving with some major squeaky brakes for a looooong time (probably 1.5 years+) So I am thinking, boy, I cant wait to get new brakes and get rid of the squeaking.

However, here I am posting this (after doing a forum search)- 500 miles after new brakes installed- crying about font brake squealing. The squealing occurs just when I come to a complete stop; just as I go from 5mph to stop. And its not a simple squeal. Its loud (and it sounds different from my squeaking brakes before the job was done.) I actually get embarrased when I am in traffic. So here's my question: before I drive back to my indie shop who did the work, what do I need to consider? is it the pads? rotors? what is the culprit? the repair guy did tell me that squeaky brakes may not be completely silenced after the brake job but this is ridiculous....I'm at my wits end right now. I could use some solid advice.

Like a lot of things in life, brake pads are a compromise; softer compounds dust more and wear faster, but are quiet. Harder compounds often "bite" better and wear longer, but are noisy. You need to check with your indy and find out which type of pads he used; shims, dampeners, and brake grease could help.

[clarksongli]

Also remember....without bedding the new pads to the rotors, you will get squeal. i would personally start there....many road pads are going to more durable material, meaning bedding becomes more important.

Both on my daily cars and my track car, i run zero shims, grease, dampeners etc. All of these products, will help reduce the squeal, but is really covering up the issue, and not addressing the actual cause of the problem.

A quick test.....find a real long straight with no traffic....

30mph-1mph - do a few of these to build temp gradually in the brakes

45mph-1mph - do a few of these, with increasing brake pressure, you should be aggressive but not enough to engage ABS

65mph-1mph - do a few of these....at this point you should start to feel brake fade as the pads start to overtemp towards the last runs

Now drive it off for maybe 15-20minutes without stopping.....fully stopping at any point is not good....it'll bed a pad shape transfer layer in a single spot, causing squealing and possible pulsing.

i have used many pad compounds, while track pads and some aggressive street pads will cause some squeal, i have never seen an oem or street dedicated pad squeal loudly.....even my track pads don't squeal a whole lot once they have temperature in them.

[TurboLove]

quick update: They are Porsche OEM pads. While I didn't do exactly what 'clarksongli' suggested I did something close enough. I have noticed a dramatic improvement when the car has been driven a bit and warmed up. However, there's still a squeal when I start out cold. I'm really hoping that it only gets better over time. Question: in case the squeal does return, what are the brand names of pads that might be softer but don't squeal? I have no clue. thanks for all the suggestions!

[clarksongli]

really any street level pad will work. stoptech makes a good pad, mintex.....anything with a low metal content really.

But it WILL get better if you can get the pads up to temp and really bed them in.....

When i swap out track pads to auto X pads, you really have to build heat to get the transfer layer to form. My suggestion is continue to with bedding...once the transfer lay has formed and is uniform again, you won't have any problems.

[TurboLove]

this update is way overdue: went back to my repair shop and discussed alternatives. Decided to swap Porsche OEM discs for Bosch. What a huge difference!! The squeal is entirely gone. The performance is solid. And a bonus- not much brake dust at all. I'm a totally believer in Bosch brakes now. Had I known then what I know now......