Metal plate behind rotors

[userbbc]

What is the function of the metal plate behind the rotors? Looks to be a shield of some sort that "should" run flat a few inches behind each rotor.
I have found that mine aren't exactly flat, and are actually pretty bent. Depending on function, wondering if it's something to worry about.

[Deep6ed]

Dust shield. Serves a purpose. Usually they are bent in a manner which hugs your rotor.

[allessence]

The metal plate is referred to as a dust sheild in most circles.

It serves 2 functions. 1) to direct air through the back of the rotor and keep the rotor at a pre determined temperature while in use. 2) to keep water /splashed water off the rotor as much as possible.


#1 Brake pads are designed to operate most effectively at a certain temperature. #2 water stuck between brake pads and rotor turns to steam and keeps the pads from contacting the rotor faces. This leads to longer degassing and is felt in the pedal and is one of many of the reasons why drilled/slotted/ recessed/ dimpled rotors give better performance They de-gas almost immediately.

[userbbc]

i guess it's worth straightening them out then? just have no idea how they could become as bent as they are...basically a wave shape moving away from and towards the rotors. Unless that's how they should appear?

[scottyuk]

We call them stone guards.

I don't go with the temperature theory as it would vary too much due to wind, angle of the road etc.

[Greg Nelson]

If you think they're 'bent' (all 4 wheels?) take your ride to the dealer and have looked at, if you're still under warranty.
Dealer s/b willing to replace if not OE shape.
Cheers

[Okan509]

I don't believe that they are bent for one second, I want to see pictures.

[hoppy6698]

They come with a natural wave in one section, its OEM. I guess if the gassing theory is correct though, when I change over to Adam's rotors, I can dump that crap - it annoys the shit out of me when cleaning the wheels and look in general.

[userbbc]

Kind of hard to get a pic with the 10spoke P+ rims without taking the wheel off but I'll try to do so when i get a chance.

Regardless, if it comes with a natural wave then it makes more sense to me. I noticed it when having my wheels straightened and the wheels were off. Thing was, a similar part was on various other audis but without the wave (A3, b7A4).

[Nght&Day-B8]

Not sure about the air flow theory, ive always heard the brake back plate is for snow purposes so snow or any debris wont affect braking.

[gqambitions]

I know this is a very old thread, but any development on this? Are they suppose to be bent? do I need to bend them back? or as long as they are not rubbing, then I have no issues?

[The Infiltrator]

Are you people serious or just trolling?

[The Infiltrator]

Are you guys talking about the bend on the shield for the front? If so it's normal!

[S4'ed]

Splash shield to reduce amount of water that can hit the brakes.....