I am a new Rx-8 owner, only 2 weeks.

I am very disapointed with the front brake rotors, after 200 miles very noticable grooves appeared in the front brake rotors.

I returned it to the dealer and was told this is normal and wil go away. I have never seen grooves in rotors go away, does anyone have experience with this?

The dealer is claiming Mazda refuses to replace them, stating that until there is at least 2000 miles this is considered normal.

I am very concerned at mazda's unwillingness to take resposibilty for defective parts on a NEW car.

I also noticed that all the new mazdas in the lot had extensive rust on the brake rotors. It seems like they are just really low quality, I knw theere is often some surface rust from cars sitting still, but at other manufacture cars there is no where near the amount of rust I am see on all the new mazdas. This seem to be a poor desing especially for a car like the RX-8 with open spoke rims, the front wheels look awful all the time.

Does anyone have any experience with Mazda and thier commitment to warrentee service?

 

Regarding the grooves in your discs, they shouldn't affect your brake performance. This happens on many cars, and although I can't say whether your grooves are normal or not without seeing them, a few light grooves is probably acceptable.

If you have a whopping great groove in the disc then there are specifications for how deep it can be in the Workshop manual (I hope! I don't have a manual here to check). If the groove is too deep, the technician may replace the disc.

Bottom line is that both the grooves and rust are appearance issues that do not affect your brakes' performance, so don't expect Mazda, or any other manufacturer for that matter, do jump up and do back flips for you.

Sorry, but those are the facts...

 

Concurring with the above.

Additionally, I noticed some grooving of the rotors in the first 800 miles or so. They worked themselves out very quickly after that and there was no effect on braking capability.

Rusting rotors is the norm for all vehicles. They are iron. Get used to it or pull them and paint the non-contact surfaces.
You can always get aftermarket rotors with anodizing if it is too annoying to you.

 

I will have to mic them and see how high the grooves are, but I have never seen grooves like this on a new car or even on a new brake job on an old car.

If I was replacing the pads on this car I would have the rotors turned to remove the grooves.

As for braking performance, Since breaking is a function of the contact area of the pad to the rotor, Wouldn't the groves increase the surface area of the rotors and provide more breaking?

_____ Figure 1

^^^^ Figure 2

For example Figure 2 has much more surface area per linear inch of the rotor.


I did look at the rotor painting in one of the other treads on here and was impressed, I will give that a try after I am resolved with the current rotor issue.

My comment was that on 2 cars side by side in the same envirioment My mazda's rotors are coated in rust, my wifes Nissan's looks like Stainless steel, (I dont think they are, but even the non contact parts are that shinny), So i figured that they are are different grades of iron, and some must be more prone to rust than others. And on a car like the RX-8 that proudly displays its brakeing system through the 5 spoke rims, I would have expected some level of effort to maintain a resonable appearence.

 

Mine only rust when I wash the wheels...and that quickly goes away as soon as I brake. It never rusts in dry weather. I don't know what the deal is with yours. Is it humid where you live?

 

I had light grooves that are no longer apparent, so no worries there for me. And yes brake rust is a bit annoying, but what is of real concern with the braking system (how well the car stops) has never been an issue and is just a shade behind my FD's braking system. This car stops very well. That is all that matters to me.

 

Unless your pads are so mushy as to sink INTO the grooves, fig2 actually has LESS surface area.. Only the tops of the grooves have contact, the valleys dont contact.

 

I would expect that the pads will wear to be a mirror image of the rotors, since the pads wear relatively fast compared to the rotor.

Then they would have full contact to the rotor surface.

 

Yes the contatc surfaces polish away quite quickly but the non contact surfaces stay rusted forever.

It is humid here in Houston, could be part of it, but as I stated my wife Nissan's rotors are spotless in the same envirioment and more time.

 

I had grooves in my front rotors early in the ownership.. but they did eventually go away. (to my surprise)

 

I had a grove in LR rotor that I pointed out to the service manager at pre-buy inspection so he'd know. He said, "Hummm". At 4700mi it's long gone, I just checked. Smooth as silk now.

Hope that sets your mind a little easier.

 

That's the nature of brake rotors. If you go with a cross drilled or slotted rotor usually they'll have some coating on the center section. You won't see rust then.

 

My suggestion for the grooves is to drive a little longer, give the brakes a pounding every now and then, and check them again in 2500 miles.

For the rust, it sounds like you may have had more rust than other members on this forum from the start. Maybe your vehicle was sitting at the port for a while before it was delivered. I suggest you take the rotors off and give them a good clean up with a wire brush (non-friction area), wipe a bit of CRC on them (OBVIOUSLY on the non-friction areas) and try them for a while.

Good luck...

 

Thanks, I will give it another 1K miles as sugested by mazda, I am very skeptical but if I am wrong I will let you all know.

I do seem to read alot about Mazda avoiding responsibilty for repairs in other threads, I am sure there is a balancing act between fixing every concern and haveing happy customers, and avoiding repairs and chasing away customers.

At this point I can't see myself every buying a new Mazda again. With as much effort and expense they go to to get a customer it is surprising how little they do to keep one.


For a car company so concerned about getting good customer satisfaction surveys I don't see it in thier actions.

 

You may be seeing dealer bad vs Mazda bad. My dealer is great. Does all I ask and more. No lip, no quibble, great service, won't stop til it's better and I'm happy

Maybe try a new dealer...

 

Maybe that is the problem, the dealer is telling me it is Mazda making nthe decision, but I have not called mazda my self yet, I was trying to help protect thier precious perfect surveys. I am up to 1400 miles and the problem is getting worse. Now If I don't hold the wheel tight when i brake the car veers to the left.

 

I'm no mechanic, but I don't think one grove in a rotor is going to cause any pull in the car one way or another. If you've ever looked at older cars rotors, some can look like the rocky mtns, and there is no decernible effect in the steering, or during braking.

What you might be feeling is 'tramlining' or the tendency for wide hi-perf tires to follow (parallel to the road direction) rutted surfaces in the road.

Or not (repeat 1st 3 words). Have the dealer take the car out and repeat the pull to the left. If smthg else, that is a definite saftey problem they should fix.

 

It's not one groove, think "ruffles potato chip" as in maybe 10 grooves, but more random in size and not equally spaced.

 

Randy,

I have a '98 Mazda 626. I had a similar problem with deep grooves in the rotors from new. A gas station mechanic doing my first smog check said they looked abnormally deep and should have them replaced under warranty. I then took it to my mechanic who I've gone to for 16 years. He came to the same conclusion. I had to take it to Mazda 3 times before they finally replaced the rotors and the pads. This was at 15K miles. I actually had to write Mazda and tell them how they were going to lose potential business in the future (I have since bought an MPV and will preorder the 2005 RX8). I did switch service reps to get the results. Try an outside mechanic's opinion and fight the battle. Oh yeah, the report finally said that there was a batch of bad (soft) rotor castings that were grooving too easily. Good luck!!! Enjoy that beautiful car!!!

 

My best firend has a Mazda 6s and he's had it in 3 times for problems with the rotors, took them til the 3rd time to agree to replace them. As far as I know it's been fine since they were replaced last fall.

 

The RE040's do tend to tramline... they are not a tire known for ride quality

john

 

I will close out this thread. As I now have new rotors and there look "normal" to me. They only have 100 miles on them but they look much better than the ones when I bought the car at 150 miles.

In the end Mazda still refused to acknowledge there was a problem with them but on the 4th visit we agree to replace the rotors on "good will", but not the pads, so I paid $100 to replace the pads, As I believe they are what ruined the rotors anyway.

I will try to go forward from here and consider the $100 in the cost of the car.

Thanks for all your input and advice here.