Disc Brake Calipers, Pads and Rotor Kits

Kits versus individual parts

A brake kit combines components that are meant to work together, such as rotors and pads, or calipers, rotors and pads. Kits save time compared with matching parts one at a time and help ensure compatible sizes. Single rotors, as in several sample listings, suit owners who only need to replace worn discs. Check the product page for exactly which parts are included and whether the pieces cover one axle or one wheel.

Rotor types

• Smooth vented rotors are the common OE-style design. They are quiet and need little break-in.
• Drilled rotors have holes that vent gas and water, and can be prone to cracking under hard use.
• Slotted rotors have grooves that clear debris and gas from the pad surface.
• Coated rotors resist rust on the non-contact surfaces, which helps in wet or salty regions.

When a kit is an upgrade

Bigger tires add rotating mass and leverage on the brake system, so many owners of lifted vehicles look at upgraded brakes. A big brake kit with larger rotors and multi-piston calipers increases clamping force and heat capacity. Check whether the kit requires specific wheel diameter clearance, because larger calipers may not fit inside a stock wheel. Universal-fit listings, such as some Trail Gear kits, should be checked carefully against axle and hub type.

Compatibility checklist

• Year, make, model, front or rear axle and brake package.
• Rotor diameter and thickness, bolt pattern and hat design.
• Whether calipers are loaded with pads and hardware, or need brake lines and brackets.
• Wheel clearance and brake line routing.

Installation notes

Brakes are a safety-critical system. Professional installation is advisable unless you have experience. Replace pads and rotors together, clean hub faces of rust, torque caliper brackets and wheel nuts to specification and bleed the system when any hydraulic line is opened. Follow the maker's bedding procedure for new pads and rotors, and test the pedal feel at low speed before driving normally.

Inspection and mistakes to avoid

Check rotor thickness with a micrometer and compare it to the minimum thickness stamped on the rotor. Look for deep grooves, blue heat marks, cracks around holes or slots and lip wear at the edge. Rotors with a runout problem, usually felt as pedal pulsation, may be warped, or the hub face may have rust or debris under the rotor.

• Do not reuse worn hardware such as caliper bolts that call for replacement, or stretched clips.
• Do not use an impact gun to tighten wheel nuts. Uneven torque can distort rotors and cause pulsation.
• Do not mix unmatched pads and rotors from different brake systems, since friction materials work best with the rotor type they were designed for.
• Do not skip bleeding when a hydraulic connection is opened.

For tow rigs and heavily loaded trucks, check that the whole system keeps up: hoses, fluid and the master cylinder. A big upgrade at the wheels does not help if the pedal feel is spongy because of old fluid. Flush brake fluid on the schedule in your owner's manual.