View Full Version : Left rear brake rotor looks weird

11-01-2009, 08:14 PM
I pulled my left rear wheel this afternoon to take a look at the brakes. I've been getting what sounds like a slight scraping noise from time to time. What I found is a very strange looking brake rotor. Half of the swept area looks exactly like it should, nice and shiney. The other half looks rusted and like it has been sitting for a good while. I checked the caliper (compressed the piston and then hit the brakes) and it seems like it is working OK. It has to be working at least some as the good half wouldn't look like it does if it didn't. The pads looked fine as well. Here's a few pictures. What do you guys think?

Bottom half looks fine, top looks rusted.

Close up of the strange looking half.

Closeup of the good half.

The other three rotors look just like their supposed to look and the car is braking OK.

11-01-2009, 10:15 PM
That's a strange one Mike. It looks like it may honestly be flash-rusting from moisture, but the deep coloration of it and only being on half is farkin weird. It's like you said, it looks as if it's been there a while.

11-01-2009, 10:21 PM
The fact that half of the rotor looks right is what is throwing me. If the caliper wasn't working at all, I'd think that the whole thing would be rusted up.

11-01-2009, 10:28 PM
Is it warped at all? It might explain a bit of that.

11-02-2009, 12:37 AM
It doesn't feel like it is. There's no shudder when you hit the brakes. I had the pads off and they appear to be wearing normally. This is what really has me scratching my head. There aren't any symptoms of any of normal items that would account for this.

11-02-2009, 04:50 AM
Are the scratch marks on the rusted upper half something that was there before, or did you inflict those?

11-02-2009, 05:39 AM
Take off the wheel spacers and check your wheel bearings, just in case. But honestly that does seem very strange...

11-02-2009, 11:16 AM
Are the scratch marks on the rusted upper half something that was there before, or did you inflict those?

I did that. They're just in surface rust. They stand out really good but there's nothing to them.

11-02-2009, 11:11 PM
OK, pulled it apart this evening and the bearing appears to be good. There's no play in it and the nut was tight. The weird thing is the back of the rotor looks just like it should, shiny all the way around. Only the front is goofy.

The e brake shoes need replaced I found. The front one was a little loose and didn't want to stay in place. Since they were worn out, I went ahead and took them off. I'll see if that has any impact.

This is crazy, all the components seem to be OK and working! :runaway:

11-03-2009, 12:53 AM
I'm curious to see if this is just some freak thing or if there is an actual cause.

11-03-2009, 01:27 AM
thats strange. has it been milled down?

11-03-2009, 01:40 AM
Lenny, as far as I know, it hasn't been turned. I know it looked fine several months ago.

I'll see what it looks like tomorrow after I drive. I don't really think it has anything to do with the E-brake shoes but I guess I'll see. The fact that the back of the rotor looked fine freaks me out. I'd have gotten a picture but with the time change it was getting dark and I was trying to get the car back together. It sucks not having a garage! :ar:

11-03-2009, 06:25 AM
lets hope its nothin too major. good luck with it.

11-14-2009, 08:59 AM
*Thread Dredge*
Are you guys serious? The pad is clearly far smaller than the rotor.

11-14-2009, 09:17 AM

If you reread his initial post and all of our responses, we're not discussing the inevitable ring of rust around the rotor hat. We're discussing the fact half the rotor's friction surface is rusty and the other (lower as pictured) is not.

11-14-2009, 01:19 PM
The pads are fine. They're the TRD pads for the rear of the All Trac.

A quick update, after pull the park brake shoes off, the problem isn't quite as bad. I'll have to get another picture but about 1/2" of the inside of the rust area now looks like it should. The rest of it isn't as badly rusted as it was but it still has rust on it. The front park brake shoe had come loose from the center retainer pin and shift a little but not enough to bind the rotor and it hadn't been that way very on long. I'm still not sure what the problem is. There's no vibration like the rotor is warped and the back side of the rotor looks just like it should.

The Captain
11-14-2009, 01:55 PM
How's the lubricant in the slide pins of the caliper?

11-14-2009, 07:04 PM
I didn't pull them all the way out but they felt like they moved pretty good. There didn't seem to be any spots where they wanted to hang up. I'll have to double check that though.

11-17-2009, 12:51 AM
couldnt hurt to get them turned then see if it comes back, but switch the rotors, put the goofey on the other side, remember to mark it before getting it cut

11-17-2009, 01:30 AM
I think I'm going to do that Joe. I had them off once to get turned but the place I went said they didn't have the adapter to put it on their lathe. I've got to try somewhere else.