CT4 BW brake question

[phdibart]

I bought a 2023 CT4 BW M6 with 6,700 miles on it. Of course, they day I take delivery, I get a "Service brakes worn" message on the dash upon startup. I didn't get that message when test driving, but I digress.

I take it this means the pads are low as the sensor is touching the rotor. Is it normal to get this message at under 7k miles? The car brakes fine with no squealing or weak braking.

Also, is there anyway to tell if it's the front or the back without taking off the wheels? I visually inspected all four corners with a flash light the best I could, and they honestly all look like there's plenty of meat left on the pads and nowhere near close to the squeal bars.

 

[DustinEarnhardt]

That would be unusually low mileage for brake pads to fail. I suspect one of the sensors has gone more so than the pads. Oddly enough, the sensors are a maintenance item and are supposed to be replaced when you change the pads anyway.

In normal operation, when the pads have worn down far enough, the sensor touches the rotor and abrades the 'business end' of the sensor and sets off the warning. If you've still got a ton of pad life left, I would look into the sensors.

 

[phdibart]

That would be unusually low mileage for brake pads to fail. I suspect one of the sensors has gone more so than the pads. Oddly enough, the sensors are a maintenance item and are supposed to be replaced when you change the pads anyway.

In normal operation, when the pads have worn down far enough, the sensor touches the rotor and abrades the 'business end' of the sensor and sets off the warning. If you've still got a ton of pad life left, I would look into the sensors.

Yeah, I was thinking, unless the previous owner tracked it, which I see no evidence he did, 7,600 miles is VERY early. I've dealt with these types of sensors on my wife's Land Rover when replacing the pads but never expected them to fail prematurely.

I guess my question would be, in that these sensors only trip when they make contact with the rotor, how could it fail if it's not touching the rotor?

I suppose I'll just have to take the wheels off and see what's going on I was trying to avoid that!

 

[DustinEarnhardt]

I would guess it's an electrical failure of the sensor itself, not that it's actually prematurely worn by dragging on the rotor.

 

[phdibart]

I would guess it's an electrical failure of the sensor itself, not that it's actually prematurely worn by dragging on the rotor.

Thanks for your help! I'll update this post when if I figure out what's going on.

 

[phdibart]

As an update, I called the dealer where I bought it, and they said to take it to a Caddy dealer to see if it's a sensor issue (or other warranty issue) or if it needs new brakes. And if it needs new brakes, they'll pay for it, so I have an appt with the local dealer.

 

[Gilley]

It's awesome that your dealer is going to pay for a Cadillac dealer inspection and brake job. That could come out to a big bill with OEM pads. There is only one wear sensor for the front pads and one for the rear.

 

[phdibart]

It's awesome that your dealer is going to pay for a Cadillac dealer inspection and brake job. That could come out to a big bill with OEM pads. There is only one wear sensor for the front pads and one for the rear.

Well, I guess I was lucky I bought it in Massachusetts because they have a used car lemon law that covers safety related items within the first 90 days. This being brake related, it's covered, and the dealer has to fix it by law. I bought it from a large Chevy dealer, so I would assume they wouldn't jerk me around over something that could open them up to liability.