Un-Kut

isn't it the same basic idea? coming back from a drive and immediately washing the car.... your brakes are hot while the cold rain water is hitting it constantly, is it possible?

Colin

I would imagine you cannot get the brakes really hot in wet weather because you don't have enough traction at the tires.

goddsmack

No because you're not really exposing the discs to the rain so much, that's why there are splash guards on the knuckle. Unless you actually start going through deep water puddles, it's not so much an issue.

Colin

True, but if you're exposed to that deep a puddle, how can you drive hard and fast enough to get the brakes that hot?

Alin10123

Exactly,
plus when your wheels are spining, there isn't much water getitng into there. Maybe a few drops. Unlike washing your car when you splash cold water on the rotors, the rain water isn't as cold, plus it's in much much less quantity.

Ellas9

Someone posted an excellent article regarding the myth surrounding warped rotors. Basically, the metal is not warped itself but the material from the pads is setting on the rotor causing for uneven brake application.

Colin

In track situations, if you apply the parking brake after a hard run, the area covered by the pads cools slower than the surrounding rotor area and possibly causing warping.

sauceman

Think of it this way. When smiths cast a sword, they shape it all up when it's red hot. Then, when the job is done, they cool it down by dipping it in the water. I imagine a soldier would be pretty pissed if that process warped his sword.

I don't imagine it will do any worst with cast iron brake disks. Not like they're made of glass.

goddsmack

Not when you are doing rooster tails, you're right, plus those are fun!

I'm talking about people that slowly drive through huge puddles during flooding.

Bert Kanne

I once developed warped rotors on a car after driving on some mountain roads and going through a cold stream. I would think this would be much more difficult to do while driving in the rain.

Alin10123

The thing with the sword though, it's being cooled uniformily when you dip the entire thing in water. When you splash a hot rotor with cold water, you are getting one complete side at best. The otherside, and possibly other areas aren't getting cooled down at all. So it is possible to be warped with the cold water.

sauceman

If you just splash it, that would only cool it superficially, but not completely, and so it shouldn't be bad at all. If you dip it completely in a large puddle of water, it wouldn't be any worst, although the prospect of possibly having the engine breathe some water in would keep me away from those puddles, and the rotors would be the least of my worries then.

CJams

I think I warped my rotors since I sometimes get a shimmy when I brake. Would that be covered under warranty?

Un-Kut

^^

yep, had the same problem a week ago, went to Acura and got rotors and pads replaced through warranty

goddsmack

I will tell you that it's a case by case situation, present it to the dealer so as if to say it was a defect in the construction of the rotor or pads. Mileage does help if it is low. Make a case saying you are extremely disatisfied yada yada yada, and I would say something along the lines that it's been doing it since you got the car and didn't think it was an issue until now since it has gotten progressively worse. Otherwise, most dealerships will say it's a normal wear and tear item and will not be covered under warranty.

frescagod

Don't Drive Your Car In The Rain! It's Not Built To Handle Moisture!!!

Alin10123

Well... when you splash it, you would cool one side of the rotor faster than the other. Since metal expands and shrinks when it heats up and cools, the theory is that it wont stay in shape.

Of course... i'v never actually done this to prove anything... so you could be right just as much as me.

Beoshingus

That's also how the curve gets put into a samurai sword. One side of the blade is thicker than the other, and when it's heated and put in cold water, it draws up towards the thicker side, thus curving the blade.

So it's possible that this could happen to the rotors because of the non-uniform shape (with the notches in the edge). However, I think it unlikely that this scenario would happen. You'd have to be racing it hard past the point of brake fade and then drive into a pond.

sauceman

Don't forget that in the case of a samurai's sword, they enter the blade in the water progressively as opposed to the common practice in an occidental type sword (usually double edged as well), wich also contributes to the curving.

But yeah, the discs would have to be red hot and rolled in the water very slowly.

I guess it could happen... but that would be also called misuse or abuse by the dealership.