Brake Noise

[rustcort]

OK, I'm completely stumped and need some advice. In late August of this year (2012) I was prepping my 2009 Pontiac Vibe for state inspection when I noticed that my front brakes were low and wearing unevenly on the one side (130,000+ miles on the vehicle, bought new). I replaced the entire front brake system on both sides (pads, rotors, calipers & hoses). The car drove great, as usual, for about 3 weeks, then developed a metal on metal sound when coming to a stop. I checked the front and rear pads for debris, and all 4 corners were fine. Sound was still there after I test drove it around town. This time I disassembled the brakes at all 4 corners, checked for metal damage (found none), reassembled, torqued to proper specs and once again took the car for a test drive. It made no noise for about 25 minutes so I began heading home, and the metal on metal grinding began again when I was coming to a stop. It is important to not that this sound ONLY occurs in the last 10-15 feet, just before the car stops completely. Next I repeated the above step and this time added a bit of red paint on the caliper bracket, caliper and dust plate to see where the metal was touching, test drove the car until the sound presented it self and continued to drive on side streets another 20 minutes. When I got home I was sure I would see scraping, but nothing. None of the red paint was scraped away. I spoke with my brother for advise (he is a mechanic and lives 4 hours way so he couldn't actually look at it), and he suggested I check the bearings. As instructed, I checked the wheels for movement at 12 & 6, and they are nice and tight. As I stated previously, I am completely stumped and at a loss, any advise would be appreciated.

[richard_v]

Not sure if this will help but I had a similar thing happen with my 08 Vibe. Turned out to be the backing plate that really doesn't seem to do anything but keep dirt and water away from the rotors on the back side as you look at the brakes from the side of the car. Try checking all the clearances. Maybe you might have bent it slightly during the caliper replacement. A little forceful re-calibration may be all you need. Hope this helps.

[rustcort]

Thanks richard_v, I'll check that out tomorrow when I get home from work (have to take the wife's Dodge Caliber...uugg!!!)

[ehoff121]

What is the composition of the replacement pads?

There have been noise complaints from Vibers using semi-metallic pads where OEM was ceramic.

[rustcort]

ehoff121, they are ceramic pads. I work part time at AutoZone and I have used their premium ceramic pads for years and never had a problem. However, in this case, I believe the pads are actually the issue. I took the car out last night after checking the backing plate and drove through as many suburban streets as possible trying to get the brakes to make noise, when they finally did I headed home and they stopped by the time I reached my house. I continued to drive around for another hour and the sound never returned. Perhaps there was a defect in the pad itself that was not noticeable by the eye. Anyway I drove the car to work today and everything sounded/functioned fine. I will be exchanging the brakes for another set the next time I'm at my part time job however.