Dirty Ford Wheels

If one wheel is getting dirtier than the others, I would suspect a sticky caliper. This is a good signal to check the brake pads for wear.

The rear brakes should produce much less dust than the front. The dust is the pad as it wears down.

The normal amount of dust really depends on the type of pad you are using. Aggressive pads tend to dust much more. However, some pads have a metallic blend to the pad that reduces dust, but they also wear the rotors out faster. Generally, I would recommend OEM unless you have a specific need for something more aggressive.

Back to your problem. I see this as a clear signal that you have an issue with one wheel's brake. The rear wheels should dust much less than the front. Excessive dust on the one rear is telling me you have an issue that needs attention.

It is good practice to drain and refill your brake fluid every two or so years. Moisture is absorbed in the brake fluid and causes oxidation and galling of the brake pistons. This causes the pistons to stick and wear the pad prematurely. I would bet that the dustier wheels has a pad that is more worn than the others. Get it fixed because the brakes are one of the most important component of your car.

Brake dust is both caustic and will eat into the aluminum finish of the wheel over time. It is good practice to clean them regularly and power wash the caliper to rid yourself of that dust before it eats the finish.

How much is normal?

Could you make that a multiple choice question?

Normal is what ever your driving style creates. They should be even on both sides of the same axle as stated above. Do you have lawn sprinklers hitting one side of your car? The water will wash away some of the loose dust on that location.

If one wheel is significantly dirtier that the other three I suspect that you have either a sticking caliper or a hung parking brake on that wheel. The source of the dirt is the rubbing of the pads against the rotors, unless you have hydraulic leaks. If you do have leaks you will be adding brake fluid regularly so if not adding fluid it is the friction by-products causing the dirt build up. What is normal, good question! It depends upon the type of friction materials used, your driving style. climate. etc.....

Being a true blue oval fan and owner the voice of experience says if one wheel is much dirtier than the others do not delay. Pull it off and inspect. If you have one bad actor chances are the others are not to far away. I believe your parking brake is part of the caliper assembly; if this is used intermittently it may have bound up slightly since this is a mechanical not a hydraulic set up.

For many years now a ceramic pad has been the OEM and aftermarket brake material of choice. Dusting can clearly be a personal issue since a ceramic pad is designed to address this specific problem along with noise, fade resistance and brake component life.

Sorry it took while to get back; and thanks for the insincere and not-so-insincere answers. I should have said, rear wheels rather than wheel on the right, albeit that the right one did show more dirty -- the rolling rears do seem to gather more than the fronts.

I checked with a Ford mechanic and, while the question seemed ...atypical to him (just like here in CR4; and just the reaction I anticipated), he opined that the accelerated accumulation on rear wheels, unlike non-recent car models, is probably not as unusual as it might seem, for reasons peculiar to recent models, including:

Rear wheels could be more affected by water (and wind/slipstream) "washing up" along the bottom underneath the car and into the rear wheels...in turn leading to more stuff shedding out onto the wheel rims

Because of braking accentuation and distribution and steering stability controls designed into recent models, including the taurus, it is no longer true that much more braking/braking force is applied at the front wheels. So, the once-intuitive explanation quandary respecting my car is no longer intuitive..