So the PPI I did on the car prior to purchase said the front rotors would need replacement soon but that the pads front and rear had 75% life left in them. There is no vibration in the pedal or anything like that and they seem to work just fine so i'm wondering is there any visual indication I should be looking for (now and in the future) to know when my rotors need replacement?

I want to keep the car up to date on maintenance and not neglect it but I also don't want to be replacing stuff randomly that doesn't need it.

Also - is it normal for these brakes to feel much less "assisted" than say a Mercedes, etc? Where you really need to use some pressure to get them to clamp down? I'm assuming it's normal so you have more control to modulate the pedal but honestly i've never driven anything similar performance wise so I don't have another point of comparison than my C-Class.

 

You can measure the thickness of the rotors to determine if they are worn and needing replacement.
Front - New=34mm / wear limit=32mm
Rear - New=28mm / wear limit=26mm
For a quick test, run your finger across the rotor to the edge - determine if there is a significant 'lip' - if yes, then replace.

I typically like to do rotors and pads at the same time - but if you switch pads halfway thru the rotor life, then you will get to a point where you may only replace pads.

Personally - brakes are important, don't try to go longer than required.

 

How many miles on them? Street only? Track?

FWIW I got some brakes like that from a guy (dealer said replace) and they were in AWESOME shape. I have run 2 track weekends on them. If the dealer says replace, send me some pics and I may buy them.



Yes, it takes more pedal pressure, modulation is not very good on our cars. The brake booster is tied into vacuum pressure from the engine and is just not very precise. Go ahead and stomp it down there though, car can take it.

 

When in doubt, replace at least the front rotors and pads. That's what I did; I'll have to follow with the rears in a couple of months.

I also noticed you have to punch the brakes a little harder than your average car. At first I thought it was because my brakes were toast but it's the same with the new rotors and pads.

 

Thank you for the input guys - i'll measure this weekend and see what needs to go! Nice to know the brake feel is normal as well.

 

Yes -- I felt this as well when I first got my car. There isn't the initial "bite" feel to the brakes. Actually, I think it's a little more risky for street driving until you get use to this. There are many occasions (e.g. driving in traffic) where you need to brake quickly and unexpectedly. Without this initial bite of the brakes, you're stopping distance might be longer -- especially if you're not going that fast to begin with.

However, I'm certain that this characteristic is much better for performance and/or track driving -- where most braking is predictable and planned for in advance. The linear feel gives you much better braking control.

 

You can also look for micro-cracks between the cross drilled holes (if you have these). This is more track oriented issue than street driving.

My next rotors will be slotted as they take more abuse and will stay with OEM size.