Brake calipers are an important part of your vehicle's braking system, and keeping them clean is essential to maintaining optimal performance. While you can use a variety of products to clean your brake calipers, WD-40 is not one of them.
WD-40 is a versatile product that can be used for a number of purposes, but cleaning brake calipers is not one of them. The main reason why you shouldn't use WD-40 to clean your brake calipers is because it's not designed to remove grease or grime. Instead, WD-40 is designed to protect metal from rust and corrosion. So while it may make your brake calipers look shiny and new, it won't actually remove any of the dirt or grime that can build up on them over time.
If you want to clean your brake calipers, there are a number of products on the market that are specifically designed for this purpose. Brake cleaner is one option, but there are also dedicated brake caliper cleaners available as well. Whichever product you choose, be sure to follow the manufacturer's instructions carefully in order to avoid damaging your brakes.