Install Brake Calipers on Car Wheels
Replacing calipers is a fairly simple process that requires some specialty tools on some cars. These instructions are merely a guide and not a substitute for professional assistance.
Steps
- Park on a solid, level surface. Concrete is best, as jacks and jack stands can sink into asphalt on hot summer days. This affects the stability of the vehicle and damages the asphalt surface. Work in a shady spot or direct sun? It will probably take a few hours to do both sides of one axle if it is the first time doing this work, so plan accordingly.
- Determine which side to do first. Assume the driver side will be worked on first for this wiki.
- Make sure parking brake is NOT engaged if working on the rear calipers.
- Chock the wheels on the passenger side of the vehicle. Place one chock block ahead of the front tire and a second behind the rear tire to prevent the vehicle from rolling in either direction.
- Remove wheel covers, hub caps, etc. to allow access to the lug nuts.
- Loosen each lug nut no more than 1 full turn.
- Raise the vehicle. Use the manufacturer's supplied jack or use a floor jack to raise the vehicle, and locate to lift only at the manufacturer's designated points on the vehicle.
- Use jack stands to support the vehicle. Do not attempt to work on any vehicle supported only by a jack. If supporting the vehicle at the axle, do so closest to the wheels. Do not support or lift the axle solely at the the differential.
- Check and reposition the chock blocks if needed, to ensure there is no room for movement of the vehicle.
- Remove the lug nuts and place in hub cap.
- Remove wheel and tire assembly.
- Open the bleeder screw with a socket or the box end of a wrench. Note: these are made of soft metal and are easily damaged. Slip a length of snug fitting clear hose over the screw to direct fluid into a container on the ground.
- Compress the piston back into the caliper using a large c-clamp. Do this until the pads are no longer pressed firmly against the rotor. Expect brake fluid to be expelled from the bleeder screw as the piston is forced into the caliper.
- Use a flare nut wrench to loosen the hose where it is connected to the caliper. Do not turn hose more than half a turn to avoid kinking the hose. (On some vehicles a banjo bolt secures the hose to the caliper, in which case the hose can be removed in this step, and step 16 may be omitted.)
- Remove the caliper from the steering knuckle using wrenches or hex sockets as required. On rear disk brakes, the parking brake is removed from the caliper and the procedure varies from vehicle to vehicle. It will not be possible to remove the rear caliper if the parking brake is engaged.
- Turn the caliper to the left to unscrew it from the brake hose after the caliper is free from the steering knuckle.
- Retain the caliper in case you need to reuse any hardware or the bleeder screw.
- Select the correct caliper for the side of the vehicle being replaced. The correct caliper will have the bleeder nut oriented at the top (or very close to the top) after being installed on the vehicle. Failure to install the correct caliper will trap air in the system. This will cause a "spongy" feeling brake pedal and possibly brake failure. Hold both calipers near the rotor, oriented as they would be installed on the vehicle and install only the caliper that has the bleeder nut at the top.
- Inspect rotors. The bulk of this brake work is the caliper and pad removal and replacement. Not servicing the rotors while accessible now is practically "negligent". Consider removing the rotor for machining (called "turning" on a lathe) to remove glazing, gouges and grooves. Well traveled rotors are often glazed and result in extended stopping distances. If the rotor is too worn or has deep grooves or has significant rust; replacement may be required (often times replacing with new rotors for $25 or so is better than machining old rotors for $15). Actual cost of machining or replacement rotors is dependent on vehicle type, supply house pricing, etc., and is a matter of personal choice. Many full service auto supply shops offer rotor machining. It is illegal however, to machine rotors that are too thin or otherwise unsafe for re-installation on the vehicle.
- Fully compress the piston and install the new brake pads into the caliper.(this step is not needed, if c-clamp was used during caliper removal)
- Attach the brake hose to the caliper making sure to use the new copper washers that came with the new caliper and fit the assembly over the rotor.
- Secure the caliper to the steering knuckle in reverse order of removal steps above.
- Finish tightening the hose to the caliper if not done already, being careful not to over-tighten it.
- Install the bleeder screw loosely. Slip clear hose over the screw to direct fluid into a container on the ground. Release the hose clamping pliers or vice grips.
- Open the hood, and monitor the fluid level in the brake reservoir. Add additional fluid to maintain the level above minimum.
- Have a helper compress the brake pedal and hold it to the floor. Tighten bleeder. Have helper pump brakes 3 times, and hold. release bleeder valve. to drain air and tighten. Repeat process until no air is found.Monitor the brake bleeder screw hose, and close the screw when a steady stream of fluid with no bubbles comes out. Remove the hose and container.
- Pump the brake pedal with the engine off until a solid feel is obtained.
- Reinstall the wheel and tire. While pressing the wheel firmly and evenly against the rotor, spin the lug nuts onto the studs "snug tight". It is not required to have the lug nuts fully tight at this point. The next step will complete this process.
- Lower the vehicle. Fully tighten lug nuts to appropriate torque specifications with the tire in contact with the ground. Tighten lug nuts in a "star" pattern; do not tighten adjacent lug nuts in a circular "one after the other" pattern.
- Fill brake fluid reservoir to appropriate level, reinstall the cover and close the hood. Remove any spilled fluid from painted surfaces quickly as the finish can be damaged if allowed to sit for even a short time.
- Repeat for passenger side of the vehicle if desired.
- Test drive. Perform brake testing at low speeds away from people and buildings if at all possible. Gradually increase speed for testing.
- Tighten lug nuts and secure wheel cover, hub cap, etc.
Tips
- If a steady stream of fluid cannot be obtained from the bleeder screw, you must manually bleed the brakes.
- Different grades of pads (semi-metallic, ceramic, etc.) may be available for your vehicle. This is the reason for wide variations of price. When comparing prices between different suppliers, make sure each is quoting the same material of pad. Generally stay away from the lowest grade (unless preparing the vehicle for sale) as they wear much quicker. Mid grades and up are best choices for vehicles that are intended to be kept for some time or accumulate significant amount of "highway" miles.
- Only freshly opened brake fluid should be used. Old brake fluid may absorb ambient moisture and when put inside your car's braking system will corrode metal parts.
- The "brake job" described above (pad & caliper replacement only) will not solve a "pulsating" brake pedal problem. Pulsations of the pedal felt when braking is indicative of a warped rotor. A warped rotor must be either replaced or machined on a lathe to make it true again.
- Consider brake work as a "per axle" job, rather than a "per wheel" job. The brakes at one wheel have been subjected to identical conditions of service, wear, etc. as the other. Barring any odd circumstance of manufacturing defect, the brake components at each wheel of the same axle can be expected to be found in the same condition. If one has failed or is failing - the other is mostly likely failing as well.
- Front brakes provide about 70% of the stopping power for most vehicles. This means that the second time the front brakes will need to be redone, the rear will probably be ready to be serviced, too.
Warnings
- Do not reuse old brake fluid.
- Seek professional guidance before attempting any unfamiliar work on your car's braking system.
- Never work under a vehicle supported only by a jack.
- Do not pinch or clamp hose, clamping the hose can lead to brake failure
Things You'll Need
- Jack
- Jack stands
- Lug Wrench or Impact Wrench
- Chock blocks
- Assortment of combination or box-end wrenches
- Hex Sockets
- Caliper Compressor on rear brakes
- Pry bar or large straight blade screwdriver.
- Vice grips or hose clamping pliers
- Brake cleaner
- Rags
- Flare Nut Wrenches
- Brake fluid
- Clear hose to fit over bleeder screw (2 feet or so)
- Container to capture old brake fluid (old soda bottle & cap)
