How clean/rust-free do disc brake spindles need to be?

[robroy]

Good evening,

When I pulled my disc brakes apart I noticed that the spindles were tarnished (light surface rust) in various patches around their surface. Then the assembly sat around in the moist air and got a little worse over time.

How smooth/clean/rust-free/perfect do the surfaces of the disc brake spindles need to be? Is it enough if I just use a light sand paper on the rust spots, clean it up, and give it a good coat of grease before re-assembly?

I know a photo would be worth a lot here; I'll take on next weekend.

Thanks very much!
-Robroy

[fordman]

never sand paper emery cloth only on machined parts.

[robroy]

Emery cloth! Okay, thanks Fordman. I'll pick up some of that.

[fireguywtc]

I would buff it off, defenitly avoid sandpaper and wire brush

[cdherman]

Why not get some new bearings (you are talking spindles and hubs here, and not the actual breaking surface of the rotors, right?) and see if the bearings will go on to the spindle smoothly. If they go on OK, then no need for lots of emory cloth. In fact, if you get happy and grind around on the spindle too long and the inner bearing race gets too loose, you can damage the spindle (well, you then have to peen the spindle to keep the races tight).

You want to emory cloth the spindle JUST enough to get the bearing on smoothly, no more.

[robroy]

I would buff it off, defenitly avoid sandpaper and wire brush

Okay, thanks! I picked up some emery cloth and a "metal finishing pad," which is made out of green plastic. I used the "metal finishing pad" to shine it up; I don't think it removed very much metal.

Why not get some new bearings (you are talking spindles and hubs here, and not the actual breaking surface of the rotors, right?) and see if the bearings will go on to the spindle smoothly. If they go on OK, then no need for lots of emory cloth. In fact, if you get happy and grind around on the spindle too long and the inner bearing race gets too loose, you can damage the spindle (well, you then have to peen the spindle to keep the races tight).

You want to emory cloth the spindle JUST enough to get the bearing on smoothly, no more.

Thanks CDHerman, that's great advice. I already have the new bearings so I'll try that. That's a great idea!

-Robroy