In all honesty, I have never seen a warped rotor, so I don't know how to identify one. Can anyone clue me in on how to spot a warped rotor? I examine my tires and brakes before and after each session during the track day, and this far, with the rotors, I've never seen anything wrong. What are some of the visual signs of a warped rotor? thx.

 

You can "feel" a warped rotor. You'll know if you have one...

You feel a vibration in the brake pedal when braking - a wop wop wop kind of thing. You won't have to ask when you have one...

 

As Black R said, you feel them. Drive about 60Km/hr (40 mi/hr) and gently apply the brakes 'till they just start to bite. If you feel a vibration, it's the brake rotors. If you feel it more in the steering wheel, it's the front rotors. If you suspect rears, push the button on the park brake lever and pull it up 'till the rears just start to drag. If it's warped rears, you'll pulsation in the lever.

Rotor warping can almost always be prevented. You could have your rotors blue with heat but as long as you drive around gently to cool them off and don't let the brakes sit "clamped" in one place when they're hot, they will stay nice and straight. I wore my stock pads out in one day at the track but the rotors are Ok because I did a cooldown lap each time before entering the pits so the rotors were reasonably cool before I stopped.

*EDIT* BTW, Type Goch. I don't use my e-brake unless I'm parked on a hill. Try sometime parking anywhere remote and leave your car in gear instead and try to move it by hand! You'll be surprised at how much force it takes...

Oh and I was about to tell DB8-R81 that feel is all one needs to diagnose brakes but then I remembered, I am an experienced pro!!! So I guess that's all I need and maybe I should've put in a bit of legalese. ***That's what I use to determine if rotors are warped or not your mileage may vary, do not attempt without a safety net, 2 goldfish in a plastic bag, a cardboard box full of feathers and an expert on the subject present*** Seriously, it's your braking system. If you aren't ABSOLOUTELY SURE, take it to an expert.

And have fun!


[Modified by Its_real&its_spectacular, 3:48 AM 6/16/2001]

 

Also, don't confuse "hot spots" on a rotor with warping. When the rotors are warped, they are warped when they are hot OR cold. You can use the test noted above to check and see if you feel any vibration.

Hot spots are spots on the rotor that expand at a different rate when the rotor heats up - like when you do a hard stop from a high speed, or when you're driving on the track. These create a similar vibration (because the thickness of the rotor isn't uniform), but ONLY when the rotor gets very hot. When the rotor is cool like in normal street usage, there's no vibration.

 

Could using the e-brake when parking cause the rotor to warp? I'm kind of weary of using the e-brake when I park my car after a long drive.

 

but you have to use the e-brake to have your car parked still..

 

after a long drive your rotors will prolly not be hot unless you used crazy amounts of braking to heat them up alot. if they are hot just leave your car in gear so it dosen't roll away when you're parked and don't put on the e-brake

 

Yes, you shouldn't use the parking brake when you get the brakes really hot (like at the track). But it can ONLY warp the REAR rotors, not the fronts.

 

you learn something new everyday

 

nsxtasy is correct about mistaking hotspots for warped rotors. I had incorrectly bedded a set of race pads, which in-turn caused hotspots. Before I got the pads up to temperature, the brakes felt fine. However, once they heated up, it was the same feeling as if the rotors were warped.

 

also overtightening ur lugnuts can cause hot spots leading to thiss

 

You can not tell just by looking at them. The proper way to check for a warped rotor is to purchase or borrow a magnetic base dial indicator and measure the run out! A brake pedal can pulse for reasons other than a warped rotor and you are only guessing if you use these symptoms to reach a determination. Don’t play with your brakes work on them properly or leave it to a professional!


[Modified by DB1-R81, 2:35 AM 6/16/2001]

 

hot spots only affect your peddle feel, whereas a fully warped rotor will vibrate your steering wheel, you will know when u have warped rotors. They get progressively worse as they heat up. Once doing a set of twisties down a mountian, my steering was vibrating like crazy, and when i almost reached the bottom it got so bad that i had to pull over and let the brakes cool. This was of cos due to my warped rotors........ suffice to say they are fucked now.

 

Well, in my mom's civic the steering wheel used to shake during breaking, and when taken in to honda, they said it was just the brake pads. So I'm thinking there has to be more than just vibrations to show warped rotor?

 

N1Spec,

"hot spots only affect your peddle feel, whereas a fully warped rotor will vibrate your steering wheel"

that would be partially correct. Hot spoting DOES cause steering wheel vibrations. Trust me, it happened to me.