[Vigilante375]

I went to the dealership for my last free oil change a while back and I've been trying to find out if what they are saying is true. If anyone who drives their ZL1 on dirt roads could chime in, I'd appreciate it. This is one a 2018 ZL1 A10.

The rear rotors have some scoring done to them and the rear pads are down to 4mm thickness while my front rotors are good and the pads are at 7mm thickness. This was brought up to me by the service person.

The service person said it must be from me driving on dirt roads. I do drive on 2 miles, one way, fairly often. I was also informed that this wasn't covered under warranty so they would charge me around $850 to replace both rotors and pads. Of which I declined and found all the parts needed for under $300 and 30 minutes or so of my time.

Now how can my front rotors and pads be fine but not the rear? Is this from the dirt road or something else? I feel this should be covered under warranty since my car is not even a year old but I'm trying to see what anyone else has seen on an issue like this.

One other thing, I changed my oil myself around 1500 miles. The dealer changed it'd 5k miles later (~5500 miles) and nothing was wrong with the pads at that time. 5k miles (~10500 miles) after that is now when this issue was brought up. I autocrossed the car once before 5500 miles.

[Dave-ROR]

I would assume near constant traction control intervention if it uses the rear brakes instead of just cutting power. Not sure what the TC methodology is on these cars though.

[closs2sx]

What dave-ror said. if you don't turn traction control off every time the car senses wheel slip its using rear brake to stop it. I turn all the nannies off when I drive my car because of this. My 1970 chevelle doesn't have any of that and it was the car i learned to drive on and I'm still here thank god

[collinms]

Originally Posted by Dave-ROR

I would assume near constant traction control intervention if it uses the rear brakes instead of just cutting power. Not sure what the TC methodology is on these cars though.

If you ran in PTM modes this wouldn't be an issue. Run in dry mode or sport 1 for street. Simply running in sport mode and driving aggressive is not the right mode in my opinion.

[Dave-ROR]

Originally Posted by collinms

If you ran in PTM modes this wouldn't be an issue. Run in dry mode or sport 1 for street. Simply running in sport mode and driving aggressive is not the right mode in my opinion.

Huh? Did you mean to reply to me? I was commenting on his dirt road driving causing TC to activate nothing about driving aggressively.

[radz28]

It used to be that some GM cars (Toyota, too, that I can recall advertising about) used a brake-force distribution system that would favor the rear brakes more than the front under regular driving so the amount of wear, from front-to-rear, would equalize a little. So it would bias the rear brakes more than the front - because the front do most of the work. I'm not sure if GM still uses that strategy...

[s.hammer]

If your car has PDR, try recording your usual driving routes to see if traction control is intervening. I just did rear pads on mine, but the rotors are smooth with no issues. Have also gone through a set of fronts so it is odd to wear out the rears first.

[Vigilante375]

I always drive on the dirt roads with traction off. So that shouldn't be an issue. Seeing as I may go 30 at most. TC intervention on a dirt road actually hinders you because you need to keep forward momentum.

I use TC every where else. Im confident in driving but I'll let the nannies help me when it's raining or a little slippery out.

I guess I'll just replace the pads and see what happens. Thanks for the input guys.

[rodrig7521]

Looking to buy this Zl1 1le, do you guys think the rotors needs to be replace soon ?

[SWZL11LE]

Originally Posted by rodrig7521

Looking to buy this Zl1 1le, do you guys think the rotors needs to be replace soon ?

Hard to tell by pictures. Take a vernier caliper and measure the rotor thickness you can also feel the rotor surface for any ridges and check to see if any spider cracks have started to appear on the rotors.

[1hprush]

Originally Posted by rodrig7521

Looking to buy this Zl1 1le, do you guys think the rotors needs to be replace soon ?

I would replace both, rotors and pads, if for nothing else, peace of mind.

[Deakins]

If there are no cracks out to the inner or outer edges run them. Those look to have had some heat in them but it's nothing compared to what a set will look like after a full on 40 min stint with a real race pad in them.

[kramard]

Originally Posted by rodrig7521

Looking to buy this Zl1 1le, do you guys think the rotors needs to be replace soon ?

This ones been tracked hard. I recall looking at this car on fb a few mo ago. Whoever tracked it knew what they were doing. I’m a monster on brakes with 6 track days and I don’t have discoloring like that. I’m JUST starting to get that discoloration ring. I would swap pads and brakes on that car ASAP. Unless the price is right you’ll probably find a less tracked zle without looking too much.

[rodrig7521]

yea that's what i was thinking they want 56,900 for this one. It only has 11K miles which is low but its been pushed hard. maybe i will pass on this one. Thanks everyone for the information.