Brake rotors warping or uneven pad deposits

[burgersandbeer]

Someone pointed out in Jack's story of a near miss that Honda Accords, including the current one, have a reputation for weak rotors that "warp." Anytime someone complains of vibration under braking in a car forum, there is a good chance for debate on whether rotors actually warp, or simply have uneven pad deposits on them. "Bedding" the pads is often recommended as a fix for uneven deposits. This more or less involves a ridiculous sequence of hard stops from near highway speeds:Â*http://www.zeckhausen.com/bedding_in_brakes.htm



What does the B&B think? Uneven pad deposits or warped rotors?

[CopperCountry]

I'd say that if you can feel the pulsing in the steering wheel or in the brake pedal, it's a warped rotor. Recently, I had a set of not-so-cheap Raybestos Advanced Technology rotors machined (to remove some corrosion spots on the inner surface,) and they went from bad to worse. Not wanting to give up on them (they still had plenty of material left,) I took them to another shop. One of the rotors was indeed "warped" really bad - but I don't think it was due to heat or stress, I think the first shop did a sloppy job machining it. The tech at the second shop trued it up with 2 very light cuts, instead of 1 big cut (too big of a cut, and the rotor can deflect when it hits the thicker portion.) In addition, I noticed that they took a lot of care in cleaning the hub flange side with a wire brush (leaving dirt/rust on the surface can induce some 'wobble' by not being mounted properly in the lathe.)
It's been about 1500 miles since the last resurfacing, and not a trace of warp. Bottom line? Find a quality shop to do the resurfacing. If they tech doesn't seem like he knows a brake lathe from a Margarita mixer, keep looking.

[troyohchatter]

Recently a friend of mine asked me to do her brakes.Â* She has a 2002 Pontiac Bonneville.Â* I orderedÂ* brakes for a 1992.Â* OOPS.Â* The pads were HUGE when compared to the 2002 and obviously didn't fit.Â* However, the rotors did fit but were substantiallyÂ*more robustÂ* The rotor was about an inch wide, divided in thirds withÂ* a section of metal about 1/3" inch, then fin, then rotor.

Meanwhile, the 2002 rotor was a LOT less metal with a lot MORE fin area.Â* I am guessing that the additional cooling was supposed to reduce the amount of metal needed.

So I returned the pads, but I put the heavier rotors on the car.Â* See, I got to thinking.Â* Prior to my cars dated 1993 I rarely replaced rotors.Â* But these newer cars, with the demand for lighter rotating mass, are lighter and thus don't cool as well.

Another consideration isÂ*how the car is used.Â*Â*Take myÂ*wife's drive to work.Â* Out of the garage, stop sign, turn, slow, stop, turn then 1/4 mile, then two stops, then a turn, then slow, then a turn and park.Â* 2 miles, and she's applied the brakes 10 times at low speed, reducing the amount of coolling available for the brakes as the car isn't moving.Â* Also, according to "Flo" and the Progressive "Snapshot" my wife brakes harder than me.

Meanwhile, I drive 30 miles one way and use my brakes a LOT less.Â* Consequently, I am doing brakes on her car about every 30-60K miles whileÂ* my DD goes way over 100K between brake maintenance.