2017~2025 CX-5 Original Front Brakes, Outside Pads No Wear, Inside Finished?

[Davidiot]

I first noticed a cyclic rubbing/dragging sound seemingly coming from one or the other of my front wheels while driving with the radio off one day. The rub seemed to be consistent with each revolution of a wheel (the frequency of the rubbing sound quickly increasing with the vehicle’s speed). This was soon followed by some aggressive steering-wheel shaking during braking, making the culprit much more certain. Only 24,000 miles since I bought my CX-5 brand-new, I wasn’t expecting to need brakes yet, much less new rotors .

Since the first 6,000 miles, though, my car’s really only seen town miles, almost exclusively stop & go, so I had to consider that perhaps this mileage could be normal, given my circumstances? Not sure how I managed to warp (at least one of the) rotors without ever hearing any warning sounds from brake wear indicators; but might that be because Mazda doesn’t install them?

I went ahead and bought new front rotors and a set of brake pads for all 4 wheels, and borrowed a pair of jack stands and a couple of torque wrenches so I could get started on doing the work myself. Having only two jack stands and the scissor jack from my trunk, I haven’t been able to take a look at the rear brakes yet; but I did pull off the fronts earlier today.

I am in SHOCK at what I found. Wtf, Mazda?

The inside pads on both the front left and front right wheels are worn down completely; while the outside pads are still almost as fat as the brand new replacements I just bought. How could this have happened with factory-installed brakes? What other parts am I now looking at having to replace to make sure the same thing doesn’t happen again to my new rotors and pads?

 

[HyFlyer]

... Yes, I’d like to know how to prevent that; but I’d also like to know how they got that way in the first place. ...

I'll get back to you when I have time to type more.

 

[Jmaz]

The threaded hole in the rotor typically takes a M8-1.25 bolt (8mm diameter with 1.25mm thread pitch)to act as a "jack screw" to loosen the rotor.

 

[Jmaz]

Your entire post was excellent information — Thank you!
Re: 1 — guy at the parts store told me they should pop back out if lubed correctly — is that wrong? Should they instead automatically retract if pulled out and released?
Re: 2 — I did that! Got my lefty-loosy, righty-tighty backwards when attempting to loosen the bolt from the opposite side (initially got more resistance than expected; mistakenly thought I’d got it backwards, and then cranked too hard the other way). Doh!

The guy at the parts store (always a source of trusted professional wisdom ---sarc) was half right in the sense that there's sufficient grease if the pins pop out and aren't binding. But the other half is that the air still needs to be burped out by lifting the edge of the accordion boot. You do not want the trapped air continually forcing the caliper (and pad) against the rotor, even if it's with a light pressure compared to braking.