Piston Slap: The wheel peel stopgap

Hagerty Community member audiobycarmine writes:

Sajeev, I have a question about removing brake-dust residue from alloy wheels. My 28-year-old car has alloy wheels, which may have been clear-coated once. They no longer are, and that may be why this residue has built up.

The best method I’ve found (so far) is using a small wire brush (shaped/sized like a toothbrush) with an ammonia/detergent mix. I’m hesitant to use the very volatile brake cleaner sprays. Any better methods? Thanks much.

Sajeev answers:

Interesting question! Most alloy wheels are like paint jobs; they have a factory-applied clear coat for protection, keeping them shiny during the warranty period for many years. And to ensure we’re on the same page, note this doesn’t apply to chrome-plated alloy wheels, as their protection lies within that plating.

Back to your question: I’d prefer using mild chemicals (like brake cleaner, relative to the real nasty stuff like carb cleaner) over metal brushes on bare aluminum.  A metal brush is more of a last resort, but I’ll admit this discussion is moot, as all care in wheel cleaning is intended to protect the clear coat. Once gone, the wheel cleaning game can become the wild wild west.

To wit, when I noticed the clear coat peeling from (then) 20-year-old alloy wheels, I scraped it all off with my finger (no scratches) with shocking ease, polished them up with polishing compound/metal polish, and then kept a coat of wax to ensure residue rarely has a chance to build up.  While the end result wasn’t as pretty as new ones, it’s more than adequate for most fully depreciated machines. The coat of wax (maybe after cleaning) will likely make bare aluminum clean up with basic stuff like soap, water, and a cleaning rag.

If you want to eventually restore this vehicle, consider spending the $400–$550 for a local wheel shop to fully refurb them. Which is what I did in the photo above, and I still love looking at those formerly dowdy rims on my 1989 Lincoln Continental. Never thought I’d say I love a 15-inch disc wheel with triangular detailing, but that’s what specialized cleaning, diamond cutting, polishing, and clear coating will do!

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