C3:Rear rotor turning

[Steve lischynsky]

I've checked the archives but can't seem to find what I'm looking for.

When turning the rear rotors, are the shops set up for turning the rotors on the spindles to maintain the 0.005 TIR? Or do you have to find some shop that specifically does this?

Thanks
Steve L
73 coupe since new

[Mike Cobine]

Re: C3:Rear rotor turning

Unless your rotors are severely damaged or grooved, I just wouldn't have them turned. Most shops are not set up to turn them on the spindle. Their brake machines are set up to stick the rotor in, not the spindle.

Of course, almost any good machinist should be able to do it in a lathe.

And I have abused brakes as much as anyone, with Ferrodo and metallic pads, braking from 180 mph down to 40, and making them glow red. And I haven't had the rotors get bad enough to turn.

[John H.]

Re: C3:Rear rotor turning

Many dealers with modern equipment and most QUALITY brake shops (not the discount brake shop in the converted gas station on the corner) have equipment that can turn rotors on the car; this procedure will ensure minimal lateral runout (assuming your bearing end play is in spec and your rotors really need it).

[Steve lischynsky]

Re:C3:Rear rotor turning

The car has been sitting for 15 years. There is heavy surface rust on the discs. But they have never been turned before.

Steve L.
73 coupe since new

[Mike Cobine]

Re:C3:Rear rotor turning

What I would do, and I'll take the flack here for saying it, is take a DA or just a block of wood and sandpaper, and knock off the heavy rust.

Then I'd leave a set of old junk brake pads in and go for a drive out in the country somewhere, preferrably away from traffic and hard, immovable objects.

When I got back, I'd put in the new good pads and not worry about them.

Your mileage may vary.

[Steve lischynsky]

Re:C3:Rear rotor turning

Thanks Mike
I'll try that when I'm ready, I'm currently doing a body off.

Nothing to loose by trying this technique out.

Steve L
73 coupe since new