My brain isn't what it used to be and I thought sure that I heard my dealer say that when it is time to change the brake pads on my MCS, that I also had to change the rotors. Is this right?

I searched through the forums and couldn't find anything on this so I thought that I would ask. The dealer claimed that the rotors could not be re-surfaced and so they had to be replaced along with the pads. This may be true, but I find it hard to believe. Of course I found it hard to believe that I was buying a car with no spare tire, but a factory included jack.......

Anyone know?

 

It's totally believable. That's the way european brakes now work, at least for BMW, VW/Audi and
Mercedes. The rotors are made more disposable than in past times and the nominal action is to replace
both pads and rotors simultaneously. The claim is that the rotors now cost less so it's not as
expensive as it seems but when you add in labor ...

 

I've heard of plenty of people that replace just the pads. If something sn't worn out there is no need to replace it. I replaced just my rear pads on my GTI when they were worn, didn't touch the rotors and things are fine.
Mike

 

Go ahead and replace the rotors, as a second set of pads on used rotors will wear out a lot faster as the rotor loses mass over time and temperatures of a worn out rotor are increased.

At the point that the pads wear out, the rotors do still have some life in them, but it really is not worth the perceived savings to have a deficient brake system down the road as that second set of pads chews away on that twice used rotor.

You can maybe get away with not replacing the rears if you really need to save a little cash. . . . . but I would not do it.

 

So then I'm curious, if the pads wear out during the bumper-to-bumper warranty, will the dealer replace the rotors too? If the answer is 'yes', then I'll buy into the mysterious disolving rotors theory. Otherwise, I'd be suspicious of getting gouged on a simple brake job. Anyway, what does the service manual/CD say about all this?

 

At the point you have worn out your first set of brake pads, the rotors should still be in relatively good shape. However, as that second set of pads continues to grind down the rotors, the performance of your braking system will begin to suffer. Brakes will not be as strong and will fade sooner as there will be a lot less mass to the rotors to absorb and dissipate the heat of friction.

Let's think down the road a bit though. If you just change the pads now, you will save a bit on parts, but will pay basically the same labor as a full brake job. What are you going to do in 6 months when your pads are still good but your rotors are ground down too far? Will you pay the same labor all over again but keep the half used pads on to avoid getting gouged on a brake job?

It just seems to me that in the long run, it costs more to do the half-*** job than it does to do it right and completely the first time and enjoy a fresh braking system that does not have potentially suspect used parts to worry about.

If costs really are an issue, you could probably get by leaving the rotors on the rears, but it really is not worth risking it with the fronts.



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My train isn't what it used to be, either. How many miles do you have on this set of pads? Is this the first replacement?

I know that once your rotors reach a minimum width, they cannot be machined. Then you will be advised that you need to replace them. (The ones I replaced, not on a MINI, cost a fortune and weighed a ton.) On the other hand, you should be able to get at least ONE machining on a set, unless you wait too long for pad replacement.

 

Somtimes establishments charge enough for resurfacing that new rotors are not too much more expensive. I would agree that there is a minimum rotor thickness tollerance that must be maintained.

I do recomed resurfacing, if not replacing to get the best results in noise comfort. This allows the new pad matieal to develop a brand new film on the rotor surface, allowing the friction to stop. If this is not cleaned off from remaining pads, vibration, and squeeling may occur.

Alex