When rotors look like this...

Can they still be taken to a shop that'll turn em and then reused?

I feel like this is a noob question, but I've never had rotors turned, and I don't think these have any grooves, just rust.

As long as they mic out and have enough meat to turn, then absolutely. Actually, if they're not grooved or warped, and within spec, just hit them with a sander and knock the rust off. The second one down looks pretty thin on the back side. I think I'd pitch that one.

Soak them in a tub of vinegar for a couple of days. The rust will just hose off and you'll be able to measure their thickness very easily.

16vCorey wrote: The second one down looks pretty thin on the back side. I think I'd pitch that one.

I noticed that too.

I've always been told that when doing a brake job, to always have the rotors turned, or to replace em, and I've always been too lazy to reuse the old rotors.

In my younger, more oblivious days, I used to just change pads and ignore rotors since the pad wear was obvious and the rotor wear wasn't, I just assumed that rotor wear was negligible.

A buddy recently got me a 50% discount on ATE pads and rotors, so I was all ready to throw away these old ones, but then I thought if they were still usable it'd be a complete waste.

You only need to replace rotors if they're worn. There's nothing wrong with throwing a new set of pads on without doing anything else.

That's what I always thought skruffy, but I was told that I've been half-assing it by a friend, and I didn't want to neglect the other half.

^NOT CORRECT!!! pads rubbing against rotors create what is called a wear pattern. if you just slap in new pads the contact patch of pads against rotors will be smaller because if inperfections in the rotor, causing you to not stop as well. it takes like 15 minutes, have the rotors cut.

Getting a clean machined surface is critical to getting new pads to bed in correctly. If you're on a budget at least scuff the rotor surface real good, but for the $9 it costs to have them turned I see no reason to skip this step.

Thats part of what you do when you bed the pads. Not only is the friction material "curing" and transfering itself somewhat to the rotor you are also contouring the pad to the rotor.

I never replace a rotor unless below specs or cant be turned out. I also never turn a rotor unless I am trying to eliminate a vibration or cure a pulse or the rotor is deeply grooved.

When I worked for Mercedes we only replaced rotors when worn out and NEVER turned any. This was by recomendation from Mercedes in Germany.

New rotors are always cheaper than a new spleen.

John Brown wrote: New rotors are always cheaper than a new spleen.

Yes, but do you replace the engine when you change the oil?

How about the master cylinder and calipers when you flush the brake fluid?

I've been informed by a few different brake manufacturers, mainly Centric and ATE, that rotors that are grooved, pitted, or rusty should be turned. A groove being 1/16 of an inch deep. Thickness variation is something else to look for. And if you don't have a lathe or can't do it yourself I would rather reuse the rotor than pay someone to machine it. I've seen a lot of rotors ruined by bad machine jobs.

Don't forget, machining the rotor reduces the heat sink capabilities of the rotor.
Unless the rotor has build up (warped) or grooved, there is no need to turn them When I replaced pads, I clean the rotor with brake clean and a light sanding. Takes a couple miles for the new pads to bed in.

I had some rotors that looked similar - no grooves, just surface rust from being stored in too much humidity. I soaked them in Evapo-rust ($20/gal from H-F) over night. All rust gone, they looked like new and pads bedded in fine.

porksboy wrote:

John Brown wrote: New rotors are always cheaper than a new spleen.

Yes, but do you replace the engine when you change the oil? How about the master cylinder and calipers when you flush the brake fluid?

Replace the driver when you open the door? Replace the tank when you refill it? I can do it too!

New rotors will always offer a better surface than machined or used units and as long as they meet the OE spec (some may not) they will always last longer than machined or used. In a performance setting using new rotor blanks will help you to stay out of trouble. New rotors are indeed cheaper than a new spleen.

The two rotors in the middle(the solid discs with the deep hat) arent really machinable. The center depth is near impossible to mount in the brake lathe and flexes when the cutting. essentually warping the rotors while resurfacing.

theres my two cents.

"New rotors will always offer a better surface than machined or used units"

what is the new rotor surface finish if it is not machined?

For what they seem to charge for brake resurfacing anymore... its almost the same price to get new rotors. At least in my applications.

If I had a lathe, I would turn my own rotors. I loved doing it. But I'm not sure of any local shops that still do that. And I dont feel like leaving my car up on stands long enough to have someone else do it.

But a brake lathe is my #1 item on a garge tool list...

captainzib wrote:

How the hell did you get into my basement?

porksboy wrote:

John Brown wrote: New rotors are always cheaper than a new spleen.

Yes, but do you replace the engine when you change the oil? How about the master cylinder and calipers when you flush the brake fluid?

dude, totally not the same thing

Rusnak_322 wrote: "New rotors will always offer a better surface than machined or used units" what is the new rotor surface finish if it is not machined?

Born from jets?

iceracer wrote: Don't forget, machining the rotor reduces the heat sink capabilities of the rotor. .

Exactly, and then you run into warping issues.

Did I stumble on to a Honda forum by accident?

I buy the $18 apiece rotors so I don't have to have this argument with myself. It's cheaper than getting them turned.