Excessive "brake dust" on one wheel cover

The right front wheel cover recently has been accumulating what I assume is brake dust grunge about twice as much as the other three wheels.

I’ve run the car through a good wash several times so know that this is a repeated ongoing situation the past few weeks.

That wheel is NOT hotter to the touch after driving than the other wheels.

No braking issues. No brake squeals or other sounds.

Fluid in the brake reservoir is normal. Brake lines were flushed and the brake fluid replaced with new fresh fluid a year ago. No signs of fluid leaks of any kind on the garage floor or inside the engine bay. Otherwise original brakes and all related brake function parts now eight years old, about 57,000 miles.

So… could the excessive accumulation of what I think is brake dust (or whatever the correct term is) be from a sticking brake caliper??? Any other source?

I do plan to mention this when I have the car serviced for an oil change in a few weeks.

As to advice given, please remember that I am physically unable to safely climb underneath the car to look at anything from there and unable to do any “wrenching” myself.

Thank you.

Have someone check if the brake hose to that caliper is acting like a check valve.

When this happens, the brake hose prevents the caliper from releasing the brake pads from the rotor immediately when the brake pedal is released, and creates more brake dust than the other wheels.


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@Tester Thank you. Will do.

I hadn’t thought about the brake hose being the issue, although as often as that is mentioned in discussions here I should have.

At eight years old, I probably need to have all degradable hoses and belts looked at.

Again, thank you!

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That corner is dragging more than the other side. Given the age, agree it could be a brake hose. Could be a sticky caliper or slides, too. I’d bet the brake pad on that side is a little thinner than the other by now.


@Mustangman Thank you.


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Yeah, brake check, caliper check, brake fluid flush.

Will have the brakes and all compinents checked.

Brake flush and all new brake fluid was done last year, less than 7,000 miles ago.

I spent some time thinking about it and I don’t have any new ideas but I thought about my last brake job. My front brake rotors looked like the rings of Saturn. Some parts of it were smooth and shiny and the other areas (rings) were rough. I can imagine that the rough spots were making extra dust. Extra dust? Is that like saying “sweet corn?”

That has nothing to do with your car, of course.

Now, back to talking about my 02 GMC half ton 4WD (TMI edition apparently). I must have been working with my eyes closed. Replaced front rotors and pads and still had shaking brakes. I worked on one brake per day and when I got the right rear wheel off the bad brake problem was obvious. I could have seen that chewed up rotor if I had looked through the great big spaces in the wheel. The problem then went away and I sold the pickup a few years later with no more problems. It did need the four wheel brake job so I felt good about spending $220 instead of the possible $1,200 to have it done elsewhere.

Good idea about the brake cable above. Another idea, the wheel cover may be more sticky than the others b/c of something or other that’s sticky is coating the surface. Try cleaning it off with some sudsy warm water.

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1 of my tires is worn much more then other 3. Evenly worn. No edge wear or feathering. Tech said it might be due to brake dragging? Well, the right front has more brake dust but this tire was on left side. I rotated it front/back and never switched sides.
All tires are at 1/2 tread and this one is at wear bars.

I think a brake hose acting as check valve is rare. More likely the caliper is not sliding on its pins to the place where the pads have equal contact and pressure against the disc. It’s not a hard squeeze that would result in a hot disc; more like a light dragging on one side of the disc that produces more pad dust on that side of the disc.

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An individual who is only exposed to the vehicles they own may never see it.

But work in a repair shop, and it’s a different story.


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It is so often suggested on late model vehicles, I was thinking this must be a rust belt problem, something to do with the crimp on the end of the hose rusting and crushing the line.

I have never seen a brake hose failure on a customer’s car, only on my own vehicle but I drive very old cars.

@George_San_Jose1 @Marnet could swap the right front wheel cover with another wheel cover. If the wheel cover attracts brake dust in a different position, and the wheel cover now on the right front does not collect brake dust, that would verify your theory. In the other hand, if the wheel cover now on the right front is covered with brake dust, then is the time to examine the brakes.

This seems like an Agatha Christie mystery plot :wink:

Jack up the front end, spin the tires, do they spin with equal resistance?

Are the brake pads on both sides the same thickness?

Final, this stuff is all “made in China” and quality control is of little concern. The pads may simply be defective and the material is softer on that wheel…which would make it thinner than the other side even though everything is functioning normally.

Backyard mechanic and I’ve seen it. A guide to hold the hose away from the shock rusted and was pinching the hose…acting like a one way valve.

UPDATE: Brakes are all good! Nothing sticking.

Both front brakes are at 7/32".
Both rear brakes are at 6/32".

Original brakes, 54,000 miles, 8 years.

BTW, brake lines were flushed and new brake fluid last oil change 5,000 miles ago.

Woohoo! So, just need to scrub that one wheel cover better and keep a watch.

All the tires have plenty of tread depth remaining too, varying. (not original tires, on the second set for several years)

7/32" left front tire
6/32" right front tire

8/32" back left tire
8/32" back right tire

Wonder if the fact I make far more right turns than left turns may account for the right front wheel cover accumulating more brake dust and the right front tire having 1/32" more wear on the tread?

Anyway, all is good! :grin:

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With those great numbers, seems you are practically driving a new car! :wink:

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