My dealer informed me I need new pads (2-3mm) and rotors (grooved and corroded) for front and back of my Bolt. The car is less than 3 years old and has only 27k miles. I don't debate the need, but something isn't right. At my first inspection with 9k miles the dealer told me the rotors were corroded and I wouldn't pass inspection. They machined them (their words) so they would pass. At that time, I asked why they wouldn't replace the rotors and was told it is GM policy to machine first. I think they should have given me new rotors at that time, but I lost there. By machining them, they removed any existing anti-corrosion coating (which wasn't working). The dealer isn't budging and GM Customer Care deferred to the dealer since it is "wear and tear". I think an EV should go well over 50k miles....my Prius made it 75k it was only a hybrid with minimal regeneration. Has anyone seen this in their Bolt or have advice? I am very disappointed in Chevy right now.

 

there is no anti corrosion coating. the ability to stop corrosion is a rotor is all about its metallurgy. Machining won't change a rotors ability to stop corrosion.
Another factor for rotor corrosion is environmental conditions; do you live in the rust belt? If you do; you need to service ie clean and lubricate the caliper pins and brackets yearly....if not, accelerated wear, irregular pad wear and bad rotor finish/corrosion will occur.

It is gm policy to machine vs replace as long as the rotor is not under min spec thickness or damaged. That is a battle you will never win. Gm will pay for one brake repair under warranty as it is consumable parts.

maybe toyota uses better metal.

 

The Volt came with FNC coated rotors. I assumed the Bolt does too. Coated rotors do exist as OEM ACDelco. Why would you say coatings don’t exist and machining wouldn’t remove the coating?

 

not familiar with fmc. the only coating i have seen is the grey coating on gm rotors that is burned off during brake burnishing.

i goggled fmc. if you read the actual process the coating is 10 microns the width of a human hair.. the purpose is to stop lot rot....rust from lack of use...sitting on a dealer lot. A surface finish that thin won't last. a rotor has 60 thousand of an inch of working thickness btw. if your surface finish was bad...the coating was gone.