Brake dust is not dirt. It is hot metallic particles fired onto the wheel under pressure, and they embed into the finish and then corrode there. That is why soap and a sponge never quite work, and why the wheel looks dull again a week later.
What works is chemistry, not scrubbing: a dedicated iron remover that dissolves the embedded particles, worked with the right brushes into the barrel and around the spokes, then rinsed. San Francisco is unusually hard on wheels because the hills mean constant braking.
Wheels are the dirtiest part of any car and the first thing we clean on every exterior job, with tools that never touch paint.
Every time you brake, the pad is ground against the disc and throws off a mix of metallic particles and adhesive compound. Those particles leave hot and land on a wheel that is also hot, and at that temperature they do not just settle on the finish — they embed into it.
Then they rust. On a silver or polished wheel that is what turns the finish a dull orange-brown that no amount of soap shifts. Under magnification the wheel is not coated in dust, it is speckled with corrosion sites.
That is the whole reason a wheel cleaner and a sponge disappoint. You are removing the loose layer and leaving the bonded one, so the wheel looks better wet and dull again once it dries.
San Francisco makes this materially worse. A city built on hills means far more braking per mile than a flat city, so wheels here accumulate faster. Add the salt in the marine layer, which keeps everything damp and accelerates the corrosion, and wheels in the Sunset or Richmond take a genuine beating.
The same particles land on your paint, incidentally. That is what makes the lower panels and the boot lid feel gritty — the decontamination guide covers that side of it.
This is what we do on every exterior job, and it is also the order to follow yourself.
Always. Wheels carry the most aggressive contamination on the car, and doing them after the paint means splashing all of it back onto panels you have just cleaned.
A wheel mitt and brushes that live for wheels only. Using the same mitt on a wheel and then a door is the single most direct way to put deep scratches into your paint.
Get the surface layer away before any chemical goes on, so the chemical works on what is bonded rather than on what would have rinsed off anyway.
A dedicated iron-dissolving product sprayed on and left to react. It turns visibly purple as it dissolves embedded particles — on wheels that have never been treated, dramatically so. The dwell is doing the work; scrubbing early wastes it.
The inner barrel is where most of the accumulation actually is, and it is the part almost nobody cleans. A long-handled barrel brush plus a soft detailing brush for the face and lug recesses.
Tyres hold old dressing and road film that will sling back onto clean paint if left. Arches hold grit that does the same.
Iron remover left on a wheel finish is not doing it any favours, and water left in the lug recesses runs out onto the paint later.
Tyre dressing applied evenly rather than slung on, and protection on the wheel face so the next round of brake dust has something sacrificial to land on.
Wheels are included in every exterior job at no extra charge. The add-ons below are for what has already bonded.
| Sedan | Midsize SUV | Large SUV / truck | |
|---|---|---|---|
| Wheels, tyres and arches | Included in every exterior service | Included | Included |
| Exterior Wash & Protection | $100 | $125 | $150 |
| Iron decontamination (paint and wheels) | $75 | $100 | $125 |
| Full Package | $279 | $300 | $350 |
Iron decontamination is the add-on that addresses embedded brake dust rather than surface brake dust. On a car that has never had it, it is the single most visible exterior add-on there is.
Not an add-on, not an afterthought — wheels, tyres and arches are done first on every exterior job with tools that never go near your paint. That order is the whole reason a careful wash does not put swirl marks in.
If the wheels have gone dull rather than dirty, that is embedded iron and it needs the decontamination add-on rather than another wash.
More short answers live on the FAQ.
The services this guide is about:
Back to the full guide library.
With tools that never touch your paint. Included in every exterior service.