I just finished reading an article on the subject two days ago in a automotive brake trade magazine. We had a discussion about it. That is why I posted the information, it is counter intuitive but 100% correct. Specifications are based on caliper piston travel. The piston will leak long before the disc will fail.

Exactly!! In my years of maintenance, I can tell you I've witnessed countless people that don't know when to check their cars until they stop working. I saw this lady with front brakes worn down so far that the brake pads was gone and the backing plate was worn half way down. The rotors were so worn to the point that the surface was gone and the cooling fins were exposed!! Yea, those rotors were bad and the calipers were still fine and not leaking.

Shouldn't really have been doing that anyway. If you rev match your downshifts, you shouldn't get much clutch wear at all.

Hang on to your misconceptions people obviously you are not interested in actual knowledge. If a trade mag from the brake industry does not mean anything the you are too far gone for me to bother with.

I was referring to article entitled " brake myths busted" in Jan 2012 edition of Brakes and Front End Magazine page 26.

It's not rocket science people.

Check rotor thickness, if minimum thickness is reached, replace.

I agree with you except I have also read trade magazines stating calipers should be changed around 100k miles and struts at 50k.. For optimum performance out of a vehicle, maybe, but in my opinion, that's crazy. Now the author was suggesting ways to make your shop more profitable, but to me that's just ripping people off. And I'm talking the normal passenger car, not our boxsters.

I agree with you Jake. I can't tell you how pissed I get when I hear of people that take their cars to mechanics for simple fixes (not asking me first) and walk away paying 10x more for things they never needed. There are people in every profession that will take advantage, it's worst when it's a profession near a dear to your heart.

^For me that's normal... anyone who has the sense to take their car to the dealership for simple maintenance items deserve to get r***ed...

Dealership don't make money selling cars, they make money doing simple oil changes and maintenance work.

I know a mechanic who works at a dealership admits to me that business is bad and service managers outright lie to customers telling them they need brakes & rotors replaced asap when they have 50% left.

But hey, I hear their free coffee tastes great and their sofas are comfy.

The article did not offer any advice on when to change the rotors it merely made the point that the discard thickness was based on caliper travel not any criteria that had to do with warpage, heat, or strength of the disk.

I understand why, if the disk is worn then there is still a friction surface to stop the vehicle, the rotors will get ruined but the car will still stop as in the case referred to where the disk was worn to the fins. If the caliper piston pops out then there is no braking system at all.

I agree a lot of trade mags are there to sell stuff but there is also a lot of good info there. If you are trying to provide a good service then you will, if you are trying to sell nitrogen to put in peoples tires then you can find that crap as well.

I believe that return customers are the best reward. People bring their cars to my shop because they trust me. Why would I want to foul that up for a lousy benjamin?