Warped rotors?

[sKunkman]

I noticed this today when going to work. Today happens to be rainy and foggy, so this could have something to do with it.

I was going about 60 and hit the brakes LIGHTLY. I get alot of shuddering - could this be warped rotors? I figure it may be amplified because of the humidity, but I don't know. I don't really notice it otherwise, only occasionally, and the fact that today is rainy may have made a difference.

[aceyx]

it can either be warped rotors or a problem with alignment or another suspension problem.

i'm not sure how it relates to humidity levels, but do you park your car outside? accumulated rust can often make the rotor wear at different rates, giving an uneven surface (what is usually called "warped," even though that's a fairly false designation).

[sKunkman]

Yeah I park my car outside usually, maybe thats something to be aware of. My parents took the garage spots :p.

I can live with the slight shuddering, like today its nice and warm and sunny and I didn't notice anything. Probably not a big deal.

[aceyx]

okay, that was worst case scenario (like you live on the ocean and leave the car in the tides) because simply leaving it outside is probably unlikely to produce the result.

anyway, the weather changed fixed it?

i'm completely stumped. how's your brake fluid level?

[marcus2116]

i could be a ball joint thats shot once go like 40 and slame on the brakes and see if it banks one way or another.

[mickd]

I know that if I am driving in rain or on wet streets and put the car in the garage in the afternoon, when I first use the brakes in the morning there is some mild grinding. It is corrosion on the rotors. Seems the heat of the rotors when the car is put away and the water that settles on them cause this overnight. It is especially bad in winter, where our enlightened snow removal, SALT, makes this condition worse. All it takes is a few good stops and the rotors are clean again and all is OK. Sounds like this might be what you are experiencing sKunkman.

[sKunkman]

Probably the most likely case... of course I can take it to my friend and have him check it out. Hopefully nothing major is wrong :) and yeah, I really only notice it in the morning I guess. Or after having my car parked for quite a few hours.

[TiredTi]

Here is a good article by StopTech about the 'myth' of warped rotors.

Steven

http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

[aceyx]

heh, i've read that article too, which explains the last part of my first post. i'll still call it warped, because it may go past people if i say "uneven brake pad deposits on my rotor."


anyway, i neglected to mention why the rust would do something like that. my car was in the shop for about 3 months (brother wrecked it, problems with insurance co) and after getting it back, the rotors had gotten so rusted that this shudder occurred, to the extent it would not go away and they needed replaced.

if this only occurs on humid days and goes away after re-bedding the pads, i wouldn't worry about it at all. if the problem is more pervasive, i would consider changing compounds or the way you store your car.

[1996 328ti]

I've been experiencing some brake shudder for the past few weeks since swapping back to street pads and 15" steel wheels after a weekend at the track.
Now that I swapped my snows for 17" wheels and after a few moderate stops the shudder is gone. But the rotors are pretty rusty from the rain we've had recently. I don't thing 15" wheels with hubcaps dry out very well.