Rotors- Why do they look like this?

[Jehovasfitness]

Past week I've noticed some white stains like a liquid on my front driver side wheel and some liquid that sprayed on the undercarriage, on the suspension and inner wheel. I chalked it up to either just detailing the car and maybe I made a mistake, but all other wheels look good. Also had recently done the steering box replaced and immediately noticed the undercarriage had liquid from that. Hosed off and recently returned, not sure if related.

Either way, not only was this wheel covered in white goop/powder, but I noticed the rotor looks unlike the other 3.

1. is this all connected?
2. what would cause this wear pattern?

I've not noticed the Jeep's braking different at all and does not pull to one side.

Pic on left of collage is the rotor in question, the other 2 are from other rotors on the Jeep. 25k miles on the odometer. A mix of city and highway.

Sponsored

 

[Glamisfan]

Pull the wheel off and look at the brake pads and caliper. Or take it to a mechanic/dealership. Something is wrong.

 

[Jehovasfitness]

Pull the wheel off and look at the brake pads and caliper. Or take it to a mechanic/dealership. Something is wrong.

Looks like something has been wrong entire time right? Like that rotor has never had a pad make contact with an inch or so

 

[Pinion]

What do the pads look like.

Either the rotor was never machined correctly, the pad isn't sitting right in the caliper, or the master cylinder isn't diverting pressure correctly. Is the brake fluid low?

 

[Jehovasfitness]

What do the pads look like.

Either the rotor was never machined correctly, the pad isn't sitting right in the caliper, or the master cylinder isn't diverting pressure correctly. Is the brake fluid low?

Not sure how pads look, just noticed this an hour ago and thought it looked off.

Fluid level is filled to max level

 

[mwilk012]

Interested in what the answer is to this issue, just for curiosity’s sake. Which wheel is the abnormal one? Rear?

Oh I see, it’s a front. Weird.

 

[Glamisfan]

In looking at the picture some more, the rotor should have been machined flat when manufactured. So it kinda looks like the rotor is too thin at the outer edge to get machined?

Or possibly the pad is defective, and that’s the pattern it created?

 

[Glamisfan]

Could be missing the brake pad altogether???

 

[mwilk012]

Could be missing the brake pad altogether???

nah the majority of the pad is making good contact.

 

[limeade]

What does the backside of that rotor look like? Same wear pattern as outer or a normal wear pattern?

 

[Glamisfan]

nah the majority of the pad is making good contact.

Could be the piston that’s making contact. It looks like I can see the rotor vents about to pop through? As in the rotor is paper thin.

 

[gato]

If I had to guess, I'd say the outer portion of the outside brake pad broke of. Visually inspect or swing the caliper and pull the pads.

 

[Left Field]

My rotors usually start looking like the subject picture after a year or two. Inside and outside, and all four corners seem affected, but not always very uniformly. Interesting and similar to the OP, minimal noticeable impact or uneven brake pull.

I drive in a lot of road salt and often while towing, so extra brake heat during very corrosive conditions which is a great way to form rust. The rust starts on the outside edge and over time works its way in. Rust is hard and abrasive and I've been of the belief that it gradually abrades an increasingly wide pad area.

A major factor might be my use case - a road salt drive, then sits (and probably rusts) for a week then repeat. When I used as a daily driver it seemed like there was less of a problem. I usually run relatively soft pads to maximize brake performance which may a contributing factor too..

Usually by the time it gets bad enough that I feel I need to do something its time for pads and turning or replacing the rotors - often new rotors as the vented fronts are usually fully clogged with rust by then (in spite of buying corrosion resistant rotors).

OP - any salt exposure? Or is it possible the white goop/powder you've noticed is corrosive?

 

[Jehovasfitness]

OP - any salt exposure? Or is it possible the white goop/powder you've noticed is corrosive?

Haven't run into salt since Feb probably and even then it was only over 1 weekend.

The white goop seemed to be etching into the wheel but soon as I used some diluted simple green (I've been using it past 3 yrs no issue) and wiped off with no trace.

 

[Jehovasfitness]

FWIW the bottom right pic has a similar issue on the passenger side, but if you have to look close, it's only maybe a 1mm width section compared to the driver side's 2" or so.

Sponsored