Wheel rims and tyres are subject to contamination from brake particles, salt and road dust on a continuing basis and are the hardest parts of your car to maintain to a high standard. Even if you clean them regularly the hidden parts of the wheel can still be corroding without you knowing.
Brake dust is a major problem for owners of cars with alloy wheels, because it is corrosive, unsightly and difficult to remove. Brake dust is the product of friction between brake discs and brake pads and is a combination of carbon fibres, metal filings and adhesive resin residues. When braking, the surface of the brake pad is worn away, producing dust that is deposited on other surfaces nearby at very high temperatures. It thus immediately embeds itself into any protective coatings including the wheel rims. The metal filings contained in brake dust will start to oxidise and corrosion starts. In this way brake dust gradually erodes protective coatings until eventually they fail. At that point the rim itself starts to corrode. This continuing erosion not only makes the rim look nasty, but it can also eventually affect the mechanical integrity of the wheel.
In order to best protect them, you should remove the wheels from the car to work on them at least annually. It is very difficult to clean and protect the rear of the rim when working with the wheel still on the car. If you only ever clean the front face of the rim the corrosion will spread from the back.
When removing each of the wheels take care. Always park on a level surface with the handbrake on and chock the wheels at the opposite end of the car to the wheel you want to remove. In addition, I always use an axle stand. Before you start I suggest you consult your manual to familiarise yourself with how to jack up your particular vehicle, including finding suitable jacking points.
When working with the wheel off the car, be careful not to let it fall over or rest with the front face on the ground as this is likely to cause damage. I use two short pieces of wood to raise each wheel off the ground when working on either face and hence give it protection.
Start the washing process by hosing off any loosely bonded dirt and grime using a hose or a pressure washer. Next scrub the tyres and rims using brushes and warm soapy water taking the time to get into all of the recesses and openings and remove all of the brake dust. The longer the embedded dust is left on the wheel the more firmly it will become attached, making later removal even more difficult.
Next, use a non-acidic wheel cleaner on the wheels. Leave to soak, agitate and then rinse off and dry. If you have removed the wheel you can now replace it and move onto the next one.
When you clean the back side of your wheels, they reflect more light off of the spokes and make your wheels look shinier. The effort is well worth it both in appearance and in saving further damage and expense.
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