pulsating brakes

[jayebeach]

i have an 06 Lt with lots of miles when I push on the brakes the front ones seem to pulsate and not like an ABS system (dont think my 06 has abs ) but at higher speeds seems to really pulsate hard then all the way to a stop is slows down it pulsates in perfect time of the turning of the wheels . so the question is is the rotor warped and is this a common issue with the aveo i can get the rotor turned for about $15 or get a new one for about $30 i wiould rather turn the old ones and put new pads on but will they warp again?.... or is this something else ?

[petrified.rabbit]

You can get two new rotors from rock auto for about $47 shipped. do that. most likely if there is something wrong that they already warped once. the removing more material will only make them hotter.

[sflindall26]

i have an 06 Lt with lots of miles when I push on the brakes the front ones seem to pulsate and not like an ABS system (dont think my 06 has abs ) but at higher speeds seems to really pulsate hard then all the way to a stop is slows down it pulsates in perfect time of the turning of the wheels . so the question is is the rotor warped and is this a common issue with the aveo i can get the rotor turned for about $15 or get a new one for about $30 i wiould rather turn the old ones and put new pads on but will they warp again?.... or is this something else ?

I has this happend as well, I went with EBC performance pads and drilled rotors. Good improvement from stock. Cost me 100 shipped.

[avguy]

Quite a few years ago I had a set of rotors warp, and the guy in the shop said that "they warp all the time now". Didn't understand that, so I poked around (this was in the days before WWW), and eventually found out that warping rotors is mainly due to lug nuts being way over-torqued. Many tire guys make sure the tires will never fall off. And after they get done, these lug nuts will also never come off using any normal tire tool either. I always remove the lug nuts and hand torque whenever I get new tires. A couple of years ago after getting a couple of new ones on the front, I ended up needing to use a 2 foot breaker bar with a pipe extension to get them off . The next time I went back to that place, I asked them to go light on the gun. Big improvement - no extension needed, just leaning hard on the bar broke them free. Rough guess would be 150 ft lbs for their "light" setting. The spec torque for Aveo lug nuts is 90 ft lbs. I've never had rotors warp again since doing this hand (re)torquing.
Get a new set of rotors and always torque the lug nuts yourself using a torque wrench. And then recheck a couple of times just to make sure everything is ok.

[petrified.rabbit]

ive never heard of the lug nuts warping rotors.. now a days, the lug nuts squeeze two flat surfaces together, i can see in the past where the tugs were part of the rotors, or the hub was just a X or cross, with spaces between them.. but most of the time warping is from heat.. whether a thin worn rotor incapable of continuing to absorb the heat.. or to vigorous braking from over uses or too high expectations.

[Thymeclock]

ive never heard of the lug nuts warping rotors.. now a days, the lug nuts squeeze two flat surfaces together, i can see in the past where the tugs were part of the rotors, or the hub was just a X or cross, with spaces between them.. but most of the time warping is from heat.. whether a thin worn rotor incapable of continuing to absorb the heat.. or to vigorous braking from over uses or too high expectations.

Certain manufacturers seem to have rotors that are more prone to warping. Mitsubishi rotors in particular.

There may be something to the lug nut theory however, as my Mitsu rotors that warped also were prone to lug nut breakage from idiots in service centers using pneumatic wrenches and over tightening them to the point where they broke off when I had to loosen them. (It's amazing how much damage an idiot can do to a car during a mandatory State inspection. You won't discover the problem until long after, when you to need to remove the wheel.)

Toyota lug nuts are superior in their design. FWIW I haven't experienced any warped rotors on Toyotas.

However, one thing that is advised about rotors and warping is this: never wash your car or spray cold water on the rotors after extended driving, while they are still hot. Not a good idea...

[avguy]

It's been a long time since I looked for info about rotors warping from over-torquing, but a quick web cruise gets all kinds of hits. I see lots of opinions both ways, and below are a couple of the ones saying it can happen. And yes, there are guys insisting that it can't happen.
But regardless of what anyone says, I'll continue to undo the lugs and torque to spec, until someone proves that hammering them on with a gun to 200 lbs is the right thing to do.

I feel a pulsation or vibration in my brake pedal... — Yahoo! Autos

How Does an Over-Torque Warp a Brake Rotor? | eHow

[Pickles]

Toyota lug nuts are superior in their design. FWIW I haven't experienced any warped rotors on Toyotas.

First gen Toyota MR2s are notorious for warping rotors when the lugs are over-tightened

[AndrewButler05]

I feel I should mention, check your front brake hoses. Also, it probably wouldn't hurt to have your rotors turned if you haven't already. About a week ago, my right front brake hose collapsed and the wheel was nearly locked up. It was acting up at random times, it would take about a dozen stops to start pulsing and dragging. Then it would eventually bleed off over a a few minutes. Hince, why it would take several "in town" stops before it would start pulsing, the pressure would bleed off.

I replaced both of the front brake hoses. I always replace things in pairs if there's more than one of said thing. lol

I always tighten my lug nuts in a criss-cross pattern, then I set my Torque wrench to 90 lbs and hand torque them in a criss-cross pattern.

My rotors have never warped since I've owned Chewy and I'm pretty sure they're the original rotors. As long as they are in good condition and aren't too thin from being turned down, that's all that counts.

Best of luck on your repairs.

Just my two cents.

-Andrew