Everyone can agree that brakes are important. Through the years, manufacturers have implemented different designs and styles of braking systems and components, but the two types most commonly used in passenger vehicles today are disc and drum brakes. When specifically examining disc brake calipers, there are two types to consider: fixed or floating.
Disc brakes are straightforward: Attached to each wheel is a round metal rotor, which spins in unison with the tires. A brake caliper is positioned to sandwich the rotor with an inner lining of brake pads that have contact with the rotor itself. When the brake pedal is pressed by the driver, a hydraulic system using brake fluid applies pressure to the brake pads, which squeeze the rotor enough to slow or even stop the vehicle as demanded. This is why brake pads are made to endure a lot of friction and heat, and rotors are designed to shed heat quickly.
Fixed calipers are fixed in place with a bracket, stabilizing them on the rotor with pistons on either side. When the brake is pressed, brake fluid pressurizes both pistons simultaneously, pushing them out to force the brake pads to squeeze the rotors.
Floating calipers are also attached to brackets and sit sandwiching the rotor, but they only have a piston on one side. When the brake pedal is pressed, fluid pushes out the piston and brake pad on one side, forcing the caliper itself to shift back on the caliper pins until the brake pad on the non-piston side is applying enough return pressure onto the rotor to stop it.
We’ll All Float On
Both types of disc brake calipers rely on the same principle of squeezing the rotor between a set of pads, but they get there a little differently. Because fixed calipers must have room for pistons on both sides (and some calipers use more pistons than others), its overall profile is bulkier and heavier. That said, the symmetry helps ensure a smoother and ultimately stronger braking process, so fixed calipers are often used to achieve high-performance braking on some models and on larger or faster vehicles that need more stopping power. Floating calipers have fewer parts, are cheaper to manufacture, lighter, take up less space and work just as well as fixed for most passenger vehicles, so they are more popular with manufacturers.
Though it might be possible to convert from floating to fixed, it’s quite a project to undertake, and there really isn’t a reason to unless you need the extra braking power for specialized reasons. The most important thing is to keep an eye on the pads’ and rotor’s condition, as both can be expected to wear down with use.
Check out all the brake calipers available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on braking systems, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photos courtesy of Blair Lampe.
Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter. In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.