Yeah, those kind of rings that early on must have been a faulty part. And whether it was the pad or rotor, one would have ruined the other.

---jps

 

I have slight rust on my rotors as well, is this mainly an asthetic problem or bad rotors? Something covered under limited warranty maybe?

Or is there some activity that causes the rust?

 

there is an activity that causes rust - but like any other case where cast iron is exposed to the elements it is to be expected. this is why i presume the people that paint their brake parts do just that - to cover up rust.

don't worry about light rusting on your rotors, it might make some noises the first few times you tap the brakes but it should usually go away.

if you're in a northern climate be especially prepared to undergo pretty serious brake work every few years. thick scaling rust is not good for your rotors but light spotted rust is %100 normal. it might look like crap with these nice big wide open 18" rims but that's about all you have to worry about.

Ray

 

Continuing my education...

Do certain rotors or material of rotors resist rusting more than others?

I've seen people with slotted and drilled rotors and there appears to be no rust. I didn't know if it was based on the material the rotors were made of, or how they were taken care of.

I live in the Dallas area, so no scaling based on climate and I wouldn't describe our climate as humid or wet

 

There are occasionally someone who experiments with different materials, but other than those new, very expensive carbon rotors, all brake rotors are cast iron.

Some rotors come coated with a material meant to resist rust. The pads wear this coating off very quickly on the "working surface". The untouched surfaces then resist rust, and the pads wear off any rust that collects on the "working surface". Normally if you're going to spend more on drilled or slotted, you'll spend a little more for such a coating.

A little rust on a rotor isn't an indication of a problem. There will normally be at least a light layer where the pad does not contact the rotor. Depending on the humidity, it will also collect on the face of the rotor after the car has been sitting, but will wear off with just a little use. But if you get out of the car after driving to work, and see a ring of rust/dust where the pad should contact the rotor, then that's normally a problem.

---jps

 

whoa there...

all companies that sell aftermarket, and even all OEM's that sell replacement rotors instruct that this coating be removed with soap and water prior to installation. this coating a rust inhibitor for shipping purposes only. when this goo comes into contact with pads and brought up to temperature it can bake itself onto the pads. This isn't good for a few things related to daily driving - mostly noise and performance. When it comes to performance brake parts the difference, according the manufacturers, is quite substantial. I haven't seen their test data but if they say to clean the crap off prior installation because it adversely affects braking performance, i would tend to follow their dirrections. :-)

Ray

 

Dude, I'm not talking about a rust inhibitor that companies put on for shipping. I'm talking about the fact that some rotors come lightly anodized, or with some similar coating that is intended to stay on the exposed surfaces (other than the braking surfaces) for a good while. It's not common, but it's out there.

---jps

 

ahhh.... hehe... </dumb>

i believe you are referring to a "gold zinc" plating that some performance rotors are shipped with. very good for rust prevention.

Ray

 

Yes, that's another option (and what I had on a set of cross-drilled rotors). Frankly, I don't know if any of them are ever actually anodized, or if people just use "anodized" incorrectly as a general term.

---jps

 

anodizing is really only associated with aluminum. it involves forming a thin layer of aluminum oxide on the surface of the metal and then dying that thin surface. the pores of the oxide are larger and accept dye better than aluminum.

i think the zinc plating is most common :-)

Ray