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Rear Brake Disc Corrosion

2.3K views 9 replies 6 participants last post by  The Aviator  
I had a similar mention as well. It particularly applies to vehicle, which are often driven underloaded, i.e. only the driver or the driver with just a front passenger and hardly any load in the boot. In these cases, the front brakes are sufficient to do all required work for stopping the vehicle and the rear ones are underused. This is, of course, applicable to normal drivers, not "boy races".
I had a similar mention as well. It particularly applies to vehicle, which are often driven underloaded, i.e. only the driver or the driver with just a front passenger and hardly any load in the boot. In these cases, the front brakes are sufficient to do all required work for stopping the vehicle and the rear ones are underused. This is, of course, applicable to normal drivers, not "boy races".
Agree, regarding 'Normal' drivers. I just don't
drive on my brakes.
Interesting, this must be a common problem as there are about five CX-30 owners near where I live (like me retired, low mileage) and all have corrosion on the rear disks similar to mine (amazing what you see and learn when out walking the dog).
Booked in for 3rd service early October so see what the dealer says and whether they try to get more money out of me. I estimate, to change the rear disks and pads myself, it would cost around £150. Did the wife's fronts on her Mazda 2 last February and that cost £ 130 for aftermarket OEM standard parts from the local motor factors. On hols soon so a job for a fine day next month i think.
 
Thanks all for your replies. Mazda UK got back to me and basically told me they were washing their hands of it. Not covered by warranty and implied it was fair wear and tear.

Now I have had 3 VW Golfs before the Mazda and 2 Seats before that and NEVER had any issues with brake corrosion within the first 2 years. Similar annual mileage as well. Where I now and previously stayed is not close to the sea and although I don't cover a huge amount of annual miles I drive my car regularly and quite enthusiastically where the road conditions permit.

I am going to take the car for a good run down a few local twisty roads I know and give the brakes a good try out (gradually upping the braking to see what happens). So far I have found that braking hard in a straight line is stable and progressive and they seem as strong as they've ever been. Perhaps the corrosion will clear up, we will see.

I have to say I am somewhat disappointed by Mazda's response and will take it into consideration when looking for my next car, probably next year.

To be honest most manufacturers would have the same attitude. Just experienced an issue very similar on my CX-30 rear disks / rotors at the 1st MOT (Three years, 10,700 miles). The MOT inspector issued an advisory for pitting to the rear disks. He mentioned it was due to the low mileage. Having looked on line seems to be a common problem.