So about a month ago I noticed the brake rotors on my car were getting "warped"; vibration in the steering wheel when stepping on the brake pedal, and later a grinding noise developed. I figured I should take care of it before my daily trips to Edmond started up again. I did some research on why Aleros (and Grand Ams, same car) warp the rotors every 12 to 18 months. It gets really annoying and expensive.
Someone on the Alero forum posted this interesting link: StopTech.
It's technical, but really good. The Cliff's Notes say that rotors outside of a race track do not warp. There is no way my 3000 pound street car in street use can warp 40 pounds of pig iron in stop and go driving.
So what is the problem? As the brakes pads deposit material into the rotor (in order to creat friction and stop the car), there can be uneven wear of the pad. This will cause build up of material in some places of the rotor. The built up material takes more heat and eventually forms a bulge of "cementite", an invisible unevenness that feels like a warped rotor. The funny thing is, if you take the cementite covered rotor to a mechanic, they will find variances in the thickness and declare it warped!
So what to do about it? Sandpaper to the rescue! You don't want to use standard aluminum oxide sandpaper, as it will embed in the rotor, making your work as pointless as me in an organic chemistry class. Use garnet paper, which as it sounds is made of crushed garnet.
First, jack up the car and get the wheel off.
(sorry for the blurry pic. it was hot and I was trying to hurry.)
Then sand rotor in all directions, not just a directional pattern with the rotor face. Vertical, horizontal, circles, do everything. Spend about 20 to 30 minutes on each rotor.
(Notice the brake pad impression? Yikes!)
Last, hit it with some brake cleaner. No, I haven't found organic brake cleaner yet....
When done, the rotors will have a slight shine again. I took the car for a test drive, and to my surprise, ALL of the noise and vibration was gone! The cheap & easy fix works.
Total cost for garnet paper and brake cleaner: $7.
Time invested: about 1.5 hours (including setup and cleanup).
Money saved vs a shop puting on new rotors: ~$250. :D
Wow, that is an awesome at-home fix! Yeah, really lame that this happens so often. The average family without your know-how, tools, and place to work on car probably sold theirs a long time ago. Do you think this metal goes to the landfill, or could it be melted down as scrap metal and turned into something else? I suppose not if it is an alloy.
ReplyDeleteThe problem with metal recyclers is they don't want stainless steel or cast iron. Rotors are kinda in between, called grey iron or pig iron. Aluminum and other alloys are worth melting down and reselling, so that is what the recyclers buy. Most used rotors probably end up in the trash.
ReplyDeleteGood luck finding that break cleaner!
ReplyDeleteI think I could do this...with a bit of supply borrowing from my family. hmm...Interesting.
ReplyDelete