Rear brake rotor question.

[macmac]

Well, Jack C and BD are both right... Rotors are machined flat, and are supposed to run dead true, but they don't, not in the real world. The rotors push the pads back because in the real world there is play in the bearings and the rotors are not perfect to less than .001, and no one machines rotors to less than 0.001 which becomes instantly .002 if there is no run out.

Then you add normal heat for an instant and rotors warp, which makes more run out.


pablo, you have satisfied me that this is normal wear and tear, and that sands have entered the inside and out side areas most, which is typical.. Just go with new pads. Since it was brakes i was more than curious since your life depends on it, but this is normal ... New pads will wear into normal in under 500 miles..

A day will come when you need a new rotor, and when you do be sure the suface area where these mount is spotlessly clean, dead flat...

[pablo]

Originally Posted by macmac

pablo, you have satisfied me that this is normal wear and tear, and that sands have entered the inside and out side areas most, which is typical.. Just go with new pads. Since it was brakes i was more than curious since your life depends on it, but this is normal ... New pads will wear into normal in under 500 miles..

Thanks for the comments. I feel like it is pretty safe to just replace the pads since this is the rear brake. This doesn't supply a majority of the braking force when you really need to stop fast. Also, since there is no chattering when the brakes are applied, the disc is not warped even if it is dished out a little.

[macmac]

Well these rotors are not made of the better steels they used to be... There is no chromium in them, that I can tell and so they rust, and seem softer.. My 1981 850 triple yammi doesn't have the rusting problem these Nad rotors do, and appear harder.

I say appear because i am not about to take a file to test, or a grinder to test, but maybe one day I will hammer forge a knife from one and test then...

If someone has a dead Nad rotor and wants to give it to me to test I could tell you more..

[Cajunrider]

Hey Pablo, How did you rear brake issue turn out?

[pablo]

I'm going to put on the new pads without replacing the rotor, but haven't had time to do it yet. I'll let you know the results when I get them changed out.

[ice793]

mine has groves in the rear rotor and squeaks a little nothing a little lube on the slides wont fix but i looked into replaceing the rotor and found they are expensive cant afford 2 bills right now so ill just replace the pads.

[macmac]

Ice, try skuffing the rotor with 100 grit sand paper is little circles by hand! By HAND!!!

That will break the glaze you can't see... Concentrate on the inner and more the outter edges.

Take a swipe on the new pads gently! Break the sharp corners of the pad meat too.. That should cut the squeal.

[pablo]

Well, I finally got around to changing my rear brake pads today. When I got the caliper off, the original brake pads still have almost 1/8" of wear left, so I left the original pads on. I am surprised that they aren't more worn after 30,000 miles. It looks like the disc is wearing faster than the pads. I guess I should have checked before I bought the new pads. :)

[dogdoc]

My bro bought new pads also thinking he needed to repalce his after 20,000 miles and his were still beefy too. they dont wear as fast as the tires. LOL

[gv550]

If the rear brake rotor measures no less than 6 mm thick, and there is no pulsing when you apply the brake then the rotor is OK to use. The pads can be run down to 1 mm.

Garry

[pablo]

Originally Posted by gv550

If the rear brake rotor measures no less than 6 mm thick, and there is no pulsing when you apply the brake then the rotor is OK to use. The pads can be run down to 1 mm.

Garry

I was concerned because the rear rotor was getting wear grooves and the front ones aren't. I guess the harder pad composition on the rear pads cause the disc to wear more. There is still plenty of disc thickness and pad thickness left and no pulsing or other problems with brake performance. I'll just keep an eye on it and see how it goes.
Pablo