How do I deglaze a rotor?

[debby]

Time for new brake pads on Brutus. I've read that I should deglaze the rotors when I put the new pads in. Supposed to improve performance and reduce squealing, they say. I've read of several ways to deglaze:

1. bead blast rotors with glass bead media
2. scrub with Scotchbrite "steel grade" pad
3. sand with 180 grit paper

I don't have access to bead blasting equipment so option 1 is out. And even if I knew what a "steel grade" scotchbrite pad was, I'd never find one here in cowtown usa. So that leaves option 3.

I did have some ordinary 180 aluminum oxide paper. I have my new rear pads so I sanded the rotor. I dry-sanded until my arm got tired then wiped it down with a clean dry shop rag. Will that work or do I need to wet sand it or something? The paper did get a little black so I guess that's a good sign...

Debby

[back_online]

If it were me, I'd find a way to use really big washers, and clamp them to my bench grinder, and let them spin, then wrap the sand paper around a block of wood. If that didn't work, perhaps I'd find some other way to get them spinning real fast, (my low speed auto polisher, or my gas week wacker all spin) or maybe take them down to autozone and have them put them on their lathe, and have them hone them just a little.

I'm not sure if you could actually accomplish much by hand with sand paper.

[duaneage]

Orbital Sander with 100 Grit works for me. Cheap and easy.

[Big T]

Debby,

What you did is fine. The black stuff is what you wanted to remove.

Be sure and sand you pads a bit, then bed them in with a couple of regular stops, followed by a hard stop from speed

Happy Braking!

[KEITH KRAUSE]

I suppose if you work at it enough, the sandpaper or emery cloth will work.
Just don't ever put them on a lathe and be careful if you use anything with a motor. You don't want to create uneven spots. As for the lathe, my '79 1000 E manual says the front rotors are about .21" thick new. The service limit is only .20" thick. That means Suzuki considers them unsafe or past the service limit at anything beyond .01" of wear. A lathe would remove too much material.
I still have my original rotors (drilled out now) with 126,000 milers so far. My micrometer says they measure right in the middle, about .205". Mine were deglazed when the shop drilled them. I don't know what he deglazed them with (should have asked) but they obviously didn't remove any significant amount of material. After 5 years and 20,000 miles, they are starting to squeal again, but just barely and under very light lever pressure only.

[Anonymous]

Another thing you can do to reduce squealing is take a fine flat file and around the edge of the brake pad file a small 45 deg angle all along the other edge. It seems to help taking away that sharp 90 deg angle from the face of the pad and the side wall. I do that to all my brake pads and it does seem to help.

[debby]

The hand sanding seems to have worked

I got the rear pads in, went for a test ride, and the squeal is GONE. Brake works great too!

I did chamfer the leading and trailing edges of the pads with a file. Don't know if it helped but it certainly can't hurt.

Will do the front when the parts come in.

Debby

[Rico]

Orbital Sander with 80 Grit works for me also.

Sometimes 60 grit. I too have drill out my rotors and a quick lick of whatever I have on my sander stops any glazing.

Rico