Chronisseur

Hey everyone,
Just had my car serviced, and it seems like my rotors are due for their curtain call. Since I got this car 20,000 miles ago, I've dreaded braking at any speed above 25 MPH, due to a careless previous owner, I'm guessing, who didn't properly bed their brakes or used them too hard. My car would shake and rumble, which always got on my nerves. Anyways, I'm looking forward to getting new rotors, and I'm probably changing out the pads as well, so hopefully I can finally experience true RX-8 braking.

I've seen quite a few threads where people mentioned having their rotors turned or resurfaced, and I was wondering why. Is that common among all cars? I'm not quite sure what the TSB for the brakes was exactly, but are these problems coming from faulty pads/rotors, or possibly drivers? I plan to take whatever steps necessary in order to ensure good brake maintenance from now on, and hope that I won't have to deal with uneven rotors again. I decided to go with aftermarket instead of stock parts, mainly because they were cheaper, and I expect they should perform just as well as the stock brakes.

swoope

iTrader: (5)

unlikely warped.

search google for pad deposits.. the brakes on this car are very, very good. what happened before you you can maybe fix..

http://www.zeckhausen.com/bedding_in_brakes.htm

start here, but dont bed the brakes. read around the site.

and if you dont mention the year, mileage and tranny on the car, you might just not post.. just a hint.

beers

Vlaze

iTrader: (14)

I have to say with the American trucks I've owned in the past warpage always was a matter of when and not if with the stock ones. It's just due to mostly the material and the type of rotor that came OEM on the vehicles. Warpage occurs from the heat and hard braking conditions over a period of time. Even being on them smoothly can contribute when applying the brakes for long duration and thus heating the rotors up longer. Many factors add to this from contraction and expansion, all year round used when in cold/hot environment say if you're on them hard on them in the winter or get off a freeway and get on them excessively with water spraying on them, worn out brake pads making metal rub on metal, etc.

What usually occurs is continual wear on the rotors at times leaves grooves which tend to not be aligned perfectly around the rotors and when applying the brakes goes over the humps in the grooves and leads to the vibrations. By getting the rotors turned or rather resurfaced, they can eliminate the grooves for a flat, flush surface for use again.

SARRAS

Never overtighten your wheel nuts - that's a known cause of warped rotors. Check your manual - wheel nuts should be 90-120 nm of torque - which is nothing like the old 'Heave Ho on the wrench' you used to do with steel wheels. I always use a torque wrench to be sure, and if any third party has been servicing the car - I always go over the lugs with the torque wrench because power tools that are worn will way overtighted the lugs.

Also don't confuse warping with re-surfacing - the latter is to remove minor grooving and pitting at time of pad changes and its done to retain brake smoothness - warped rotors generally must be replaced - they can't be saved by 'shaving'

rodjonathan

iTrader: (6)

most unlikely warped more like they need resurfacing so try that first our oems are great quality and they shouldnt warp unless you did something seriously wrong

justjim

Read the Brake FAQ above https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/brake-faq-167264/ , pay particular attention to the discussion of the "myth of warped rotors". You don't say what the total mileage on the car is. Your difficulties could be anything from uneven pad deposits caused by the previous owner overdriving whatever pads they had on there to worn wheel bearings. A close look at the rotor face may give you a clue to whether you are dealing with uneven pad deposits or something more sinister.

kersh4w

iTrader: (3)

i was under the impression that sitting on the brakes while they are hot will warp them. like if you brake very quickly to a stop light, and sit with the brakes really pushed down on the rotors for a minute or two. after 20k-30k miles it will start to really affect the rotors.

Chronisseur

I know about the myth of warped rotors, and have read the brake FAQ, hence the quotation marks in the subject title. I have a 2004 with 72,xxx miles and 6 speed. Don't really think it's relevant for posting, but there you go. Since I got this car, I have been engine braking a lot because the vibrations really get to me. Perhaps I should have thought about resurfacing earlier, but the rotors are beyond the minimum thickness for the shop to do them now. I just ordered a set of slotted rotors for a reasonable price, and I will most likely be getting ceramic brake pads soon. I know the stock brake components are very effective, as even with brakes that are past their prime, I've had some pretty hard emergency stops.

swoope

iTrader: (5)

yep,

you are right, that was a silly question. good luck with your vibrations..

beers

Chronisseur

Uh, they're going away in a few days, but I'll enjoy em while I got em!

I didn't think my car's information would be helpful, because I don't even know how old the car was when they started up with these vibrations. All I know is it was before 52,000 miles or so. I'm sure many are running on stock brakes with higher mileage without problem, which leads me to believe it's the driver's problem.

swoope

iTrader: (5)

just a hint.

any issue, the history is important..

some of use know secret stuff that might fix the problem if the info is known.

about your post. at 71k miles, if your car is street driven it is unlikely that your rotors are below spec..

if they are.. the previous owner beat the crap out of it, or dragged the brakes..

maybe hook up with someone with an rx8 local that can help.. or maybe pull the wheels off an take a few shots of the rotor to brake pad area..

do you have any idea of what pads are on it now?

beers

justjim

Might look under the car for evidence of chunks of racing rubber stuck in odd places. The car may have seen the track on OEM pads, hence the possible pad deposits and rotors below minimum thickness. I asked about the mileage because a high mileage car might have other problems like a bad wheel bearing or suspension component or bent wheel that might cause pulsations. A low mileage car would most likely be uneven pad deposits.

xvickx

GREAT GUIDE
!! Thanks a bunch!

justjim

Doing what you describe above will not warp the rotors. What it may do, particularly at the track when brake temperatures are still high after a run, is weld an imprint of the pad material to the rotor face. This imprint, which is visible to the naked eye, puts an uneven layer of pad deposit on the rotor face which causes the pulsing pedal that everyone misinterprets as the "warped rotor". In a worst case scenario, particularly with rear e-brake use on FWD cars, the pad will stick so hard that the rear wheels will drag when you take off!

Chronisseur

You're right. The history of the car is important, and I wish I were the one that put all the miles on the car, as it seems like the previous owner put some heavy wear on the brakes quickly. If the stock rotors are supposed to last past 75,000 miles, sadly it will not be done in my case.

If I were more mechanically inclined, I would try to replace the rotors and pads myself, but I doubt I have all the tools and skills. I don't know what pads are on there now, but they seem to have some life on them, according to one place I went to. The dealership told me the front ones were 7mm from "the sensor", and the rears were 2mm away.