Front brake issue

Hi everyone, new to the forum.

2009 CX 9 Grand Touring, 76k miles.

I bought this about 2 months ago. When I test drove it, the front brakes made a horrible grinding. Not a big deal, I figured it just needed new brakes.

The dealership (a Dodge dealer) put on brand new pads and rotors from NAPA.

After about a week, they were grinding again, but only when braking slowly (like turning into a parking spot or driveway). I took it back to the dealer. They claimed there was a burr on one of the rotors, so they cut it, put everything back together. They said they drove it, the noise was gone.

I drove 10 miles home, and it came back.

So, I took it back. They took off the rotors and pads, did the anti-squeal stuff, etc. They drove it, said it was fine.

I drove it 10 miles home, and it came back. Drove it to work the next day (45 miles round trip) and the longer I drive, the hotter the brakes get, the worse the grinding is. The grind is exactly what my old 83 Mazda RX7 sounded like when the pads were worn down to the rivets and the rivets ground grooves into the rotors (I was 16 and dumb at the time...)

So, I took it back again. And again. It has now been to the dealer 6 times in 2 months. They went to the Mazda dealer and got factory rotors and pads. It was fine for about 3 days, but now it's right back to what it was doing.

Slowing on the highway is fine... Slowing from 45 to 5 mph is fine... It seems to just grind from 5 to 0 when braking slowly. Slam the brakes at 5, and it's fine.

At this point, I'm wondering if it's caliper related. I've done some searching here and saw that the factory brakes have a bad reputation, but brand new stuff should last more than 300 miles. The dealer keeps having me bring it back and they keep trying to fix it (at no cost to me), but this is beyond obnoxious.

Any ideas?

There are TSB on grinding brakes for earlier model.
My '08 went thru those for both front and rear brakes.
Not sure if '09 is also included in the TSBs.

Just talked to the dealership, they are putting new calipers on it next.

OK, so it now has brand new rotors, pads and calipers. I'm still getting an intermittent grinding/hum out of the front, especially at the end of my commute (45 miles) and heavy traffic.

At this point, I'm thinking front hub/bearing. Any ideas?

The dealership just seems to swap parts, they aren't really investigating the issue. They have agreed to let my personal mechanic actually investigate it and they will pay the cost.

It sounds like there is a blockage somewhere in the system (probably the master cylinder) that is allowing fluid pressure to actuate the calipers but not allowing them to bleed off pressure when the brake pedal is released or when the fluid expands upon heating up.

I think your on the right track with the wheel bearings.

If they are swapping new parts at no cost to you, then I wouldn't mind, as long as they fix it in the end. Can you tell if one disk or hub is hotter than the other? That might indicate that the bearing is bad or if the caliper is sticking for some reason... even if its new, like one of the previous posters said.

Or, going on a limb here, do you have the stability control light coming on? Maybe your wheel speed sensor is bad, and stability or ABS control applies brakes on one wheel on its own?