Rotor Turning

[clemsongt]

So I am in need of a brake job and think I'll do it over my spring break. I have looked at my rotors, and since I think they have never been turned, I think that would be ok. Does anyone know what the minimum thickness of the rotors should be after getting turned? The rears start out at 12 mm (0.472 in) and mine are 11.07 (0.436 in) thick.

Thanks

[audimeister]

Service limit is cast into the hat of the rotor. You can see it if you take the wheel off.

Turning is probably not necessary unless the rotors are in unusually bad shape.

[clemsongt]

It's always good practice to get rotors turned when changing pads...it prolongs the life of the pads.

+1 imaginary rep for the response.

[elwigglero]

It's always good practice to get rotors turned when changing pads...it prolongs the life of the pads.

+1 imaginary rep for the response.

Actually, you're supposed to replace your rotors when you change out your pads. Re-using rotors by turning them isn't the end of the world, but it's far from "good practice", especially if you're planning to use a performance oriented brake pad.

[audimeister]

I understand both of these standard responses, but everything is a tradeoff.

Perfectly smooth rotors glaze more easily. Less material in the rotor from resurfacing means it sinks less heat, and cools down faster.

Not saying any of the approaches are wrong, just different. I've been doing this a long time, and people are so quick to parrot back the standard wisdom response, they don't take the time to understand what's really going on.

It's like the answer to every suspension question is, "you need coilovers" when most of the people making that reply have coilovers that are set up wrong.

[Matt@EuropaParts]

I've had some people say new pads on old rotors is fine, others want new rotors with new pads. Just depends if you want to spend $70 on a new front rotor (http://www.europaparts.com/audi-a4-p...ls-brakes.html)

[illegitimus]

I've had some people say new pads on old rotors is fine, others want new rotors with new pads. Just depends if you want to spend $70 on a new front rotor (http://www.europaparts.com/audi-a4-p...ls-brakes.html)

that reminds me that I might be looking at a brake job this spring when it gets a bit warmer. the insides of my front rotors have developed a big lip, probably close to 3mm; the outsides are getting there as well. I am not going to turn them. I think, it is just as cheap (well, not exactly but if you factor in down time, running to a machine shop, etc) to replace them. so, question for you, those hawk hps pads are ok for not-so aggressive driving and plain zimmermann rotors all around?

[clemsongt]

I understand both of these standard responses, but everything is a tradeoff.

Perfectly smooth rotors glaze more easily. Less material in the rotor from resurfacing means it sinks less heat, and cools down faster.

Not saying any of the approaches are wrong, just different. I've been doing this a long time, and people are so quick to parrot back the standard wisdom response, they don't take the time to understand what's really going on.

It's like the answer to every suspension question is, "you need coilovers" when most of the people making that reply have coilovers that are set up wrong.

Yeah I understand. And I can agree for some cases. I have seen new pads be put on old rotors do fine. I have also seen new pads on old rotors wear out really quickly. As a rule of thumb, I like to resurface my rotors because I know in the least it will not hurt the life of my pads.

I've had some people say new pads on old rotors is fine, others want new rotors with new pads. Just depends if you want to spend $70 on a new front rotor (http://www.europaparts.com/audi-a4-p...ls-brakes.html)

Thanks for the link, but I want to avoid buying new if at all possible...I'd like to be able to turn my rotors to avoid this.