Brake rotors rust coating

[Ken Valkyrie]

My 2009 ST had a fair amount of rust on the rotors yesterday when I was getting ready to replace my front tire and put on new front pads.
Although I never had this much rust in the past, I believe the heavier rust this winter is the result of the moisture/humidity from our wet or snowy cars in our garage.
We park 2 cars and my ST in the garage.
Over the last 2 days I have mounted a new PR4 GT (front) and installed front brake pads. (getting slower as I get older)
I took a nice ride this afternoon, about 40 miles after getting everything reassembled. Temps crazy in MA, in the 60's the past 2 days.
When I got home I lightly wiped my rotors with some Honda spray wax to hopefully keep the rust away. I didn't know what else to use.
I would appreciate any suggestions you have on protecting the rotors from rust without wrecking the brake pads.

 

[Larry Fine]

I would think wax is the wrong substance to put on braking surfaces. I would clean the rotors and replace the pads.

 

[Bush]

Using the bike will keep the rust away. Agree with Larry on this. You don't want anything on the rotors that inhibits friction. If you want to clean the rust off, use lacquer thinner. It will evaporate and leave no residue.

 

[ST Gui]

Using the bike will keep the rust away.

+1 I had a Ducati with cast iron rotors. They rust if I was drinking a soda too close to the bike. They cleaned up nicely at the first touch of brakes. I did wipe them down occasionaly with dedicated disc brake cleaner sprayed on a rag or blow the dust out with compressed air. Had to be a little careful not to breath too deeply when doing that.

But I never removed the pads to clean them. The rust dust was just part of the riding experience. I've never experienced rust on Honda rotors but I guess that's the difference in the weather and the fact that out here bikes don't have to sit through a season of rain.

 

[caldercay]

When I got home I lightly wiped my rotors with some Honda spray wax to

Please say you didn't.

I'd now put brake cleaner to the rotors ... and the pads...

 

[dduelin]

I'm pretty sure the OEM rotors are a stainless steel alloy. They may show a slight brown staining over time when not being used but the brown stain actually a good thing. The chromium content in the SS alloy oxidizes to form this brown stain which is a protective coating for the rotor. This layer of chromium oxide protects the iron in the rotor from rusting and pitting. The first ride of spring should wipe the rotors clean.

Don't wax them.

 

[Kevin_56]

I'm pretty sure the OEM rotors are a stainless steel alloy.

My 07 rotors are very magnetic. Pretty sure they are not 400 series SS, which is slightly magnetic.

 

[SMSW]

+1. I too thought the rotors were stainless. In any case, they do not rust anywhere like the rotors on our Toyota. In the winter the salt on the roads and spray will cause them to rust overnight, and every night until a bit rain washes the roads clean. Even my Guzzi rotors rust a lot more than the ST's - and both bikes sit side by side in the garage (which is heated to 40 deg F to prevent a drain line from freezing). Tho, I admit my bikes do not go outside inthe winter.

One point. I have some heavy steel sitting on top of some wood near the cars in the garage. It rusts relatively quickly in the winter - prob because the salt on the cars attracts moisture more than a simply wet car w no salt.

 

[Al Gully]

Hoping you haven't use your brakes yet to transfer the wax to the pads.
Wipe the rotors down with mineral spirits and if you used your brakes, pull your pads and wipe them down too.

 

[ST Gui]

When I got home I lightly wiped my rotors with some Honda spray wax to hopefully keep the rust away. I didn't know what else to use.

Yeah I think wax even a light coat would be a bad idea. A big maybe - maybe if you wiped the wax on the rotors without spraying and getting any on the brake pads you could use brake cleaner on the rotors before your next ride. That would mean that the points where the pads were on the discs at that point might develop some rust but that could easily be cleaned off.

But I really think rust on the rotors isn't a real problem unless it was there for a whole damp winter season. Then you might want to do something to protect them for the off season if you have on.

I'd be more concerned about rust on the pins and pistons and would want to check them on a regular basis if you see rust on the rotors. Rust on the rotors will clean up with a couple of applications of brakes. Rust on the pins or pistons might affect the ability to apply the brakes. Or unapply them.

 

[Upt' North]

It's all been said, but I'd wipe it all off with brake cleaner ASAP. I wouldn't have thought it would have soaked into the pads. Might be an idea to put some sand paper, fairly fine grit on a known flat surface and just clean the surfaces by light rubbing of the pads. Move the pads not the sandpaper.
Good luck and don't worry about the rust but be gentle when you first apply them because they may grab.
Upt'North.

 

[Ken Valkyrie]

Thanks to you all: NO MORE WAXING MY ROTORS.
I did not spray it on, I sprayed it on a paper towel then wiped it on. Obviously by the response here it was a bad move on my part but it was a light coating
I'll clean it off today - thanks for your help.

PS my pad change & tire change were routine planned maintenance.

 

[red one]

Was out in the garage today looking at my ST1100 that's been in total hibernation for 3 months now. With our wet and snow cover cars my front rotors are nice and shiny. The rear looks good.....no rust. I concur with the others do not put anything on your rotors.

 

[dwalby]

California is the worst place in the world to live, but between the 12 month riding season and the low humidity at least our brake rotors never rust.