ScottArizona

O.k. guys, I need some expert advice. I have an intermittent brake squeal, actually, more like a "tweeting" or chirping that occurs when the brakes are NOT being applied. As far as I can tell, the sound appears to be coming from the rear wheels, and it goes away if I apply the brakes (regardless of pressure). I've also notice the sound will go away if I apply the handbrake. I've also noticed (although it may be my imagination), that the frequency of the sound and pitch is altered when I turn or go offer camber. The last observation is that if I don't use my brakes for a while (like if I'm cruising on a freeway without having to brake for over ten minutes), the sounds seems to go away.

I've changes front brake pads and rotors, and recently changed rear pads (but not rotors...maybe I should?), and checked for rubbing from the dust shields. It is very annoying, and embarrasing, and I'm about to give up and take it to the mechanic.

Before I do so, any advice of what I might check or try? Thanks guys. Scott.

himself

I'm sure there are gurus here on this point, but my understanding is that high performance pads make noise almost all the time. You can alleviate it by getting "lesser" performing pads, but there is a fine line between function and annoyance. I moved to Sport Pads (similar to Pagid Blue) and they emit a high pitched squeal intermittently. But, there's nothing you can do about it...

-td

Barn996

Knock on wood, I have no break squeal with stock pads.How many miles on rear rotors?

evansaero

Did it start before or after you replaced the pads?

If after:
I would remove and reinstall rear pads.

ScottArizona

Thanks for the replies. The noises started about a week after I installed my front pads and rotors, about 4k miles ago. There has been no change since I replaced the rear pads (two weeks ago). I don't think this is something that is normal because my stock pads (before changing them out), would indeed squeal, but never when I was not applying the brakes. As mentioned above, this squealing is different, as it only occurs when I'm not braking. The rear rotors are pretty worn, but the lip is only about half the size as was the lips on the front when I replaced those, which is why I haven't replaced the rear rotors...yet. THanks again.

LVDell

What about the metal shields on the interior side of the rotor? Are they bent inwards and barely touch the rotor?

ScottArizona

Dell, I checked those too, per a recommendation on this board a while back (I call them "dust sheilds"). They did not appear to be touching anywhere, and I actually bent them inboard just to make sure. BTW, congrats on the new addition. We have our third 7 weeks ago. Yup, not much sleep right now...but it gets better with every day!

1999Porsche911

Check the springs on your brake shoes. Make sure rear pads are properly seated and not floating.

Steven C.

I have not had the rear pads off yet on my car but from the parts catalog it looks like they use the spiders that glue to the back of the pads and clip into the caliper pistons. Did you re-use the ones that were there of buy new ones? These are there to keep the pad from moving when no pedal pressure is applied to prevent exactly what yours is doing. You should also use brake grease and grease the ends of the pads where they touch the caliper as vibration along with metal to metal contact between the pad and caliper is the problem.

ScottArizona

1999 and Steve, thanks for the suggestions. Where would the brake shoes springs be located...I didn't see anything that resembled such a thing when I did the pads.

Steve, I didn't notice anything like what you described...nothing seemed to click in/out of the caliper pistons...rather, it seemed just like the front, that is, the piston appeared to contact the dampners that were glued to the back of the pad. However, I didn't pull them out, so maybe I do need new "spiders." I'll check and report back. Thanks again.

Steven C.

Here is the parts catalog page for you to see what we are talking about

http://www.boardwalkag.com/catalog/C...SA_KATALOG.PDF

1999Porsche911

They are inside the drums which are part of the rear brake disc. That is where you emergency brakes are.

aben8057

It could also be a warped rear rotor..do you track the car

Mfletch

Scott, sorry to hear you are having brake squeal problems. I went through the same thing...it drove me nuts. I used the Mintex red box pads and mine squealed like a pig (I went back to OEM). 99 and Steve both gave you good advice. If you didn't take the rotors off, you never saw the emergency brake drum...it's on the inside of the disc (hub?). I tried to re-use my anit-vibration hardware. It didn't work.
If all else fails, call Sunset Porsche in Oregon. Their price for OEM rotors, pads, wear sensors, and anti-vibration hardware was very reasonable ( I think it was around $350 for everything on the rears). I couldn't be happier with my new brakes. Good luck, Mark.

evansaero

How do you know it is the rear brakes? What leads you to the rear brakes