Brake disc — inspection, removal and installation Ford F150
Warning: Dust created by the brake system is harmful to your health. Never blow it out with compressed air and don’t inhale any of it. An approved filtering mask should be worn when working on the brakes. Do not, under any circumstances, use petroleum-based solvents to clean brake parts. Use brake system cleaner only.
Inspection
1. Loosen the wheel lug nuts, raise the vehicle and support it securely on jackstands, then remove the wheels.
2. Remove the brake caliper as outlined in Disc brake caliper – removal and installation. After removing the caliper bolts, suspend the caliper out of the way with a piece of wire.
3. Visually inspect the disc surface for score marks and other damage. Light scratches and shallow grooves are normal after use and may not always be detrimental to brake operation, but deep scoring requires disc removal and refinishing by an automotive machine shop. Be sure to check both sides of the disc (see illustration). If pulsating has been noticed during application of the brakes, suspect disc runout.
3 The brake pads on this vehicle were obviously neglected, as they wore down completely and cut deep grooves into the disc — wear this severe means the disc must be replaced
4. To check disc runout, place a dial indicator at a point about 1/2-inch from the outer
edge of the disc (see illustration). Set the indicator to zero and turn the disc. The indicator reading should not exceed the specified allowable runout limit. If it does, the disc should be refinished by an automotive machine shop.
4a Use a dial indicator and rotate the disc to check disc runout
4b Using a swirling motion, remove the glaze from the disc surface with sandpaper or emery cloth
Note: The discs should be resurfaced regardless of the dial indicator reading, as this will impart a smooth finish and ensure a perfectly flat surface, eliminating any brake pedal pulsation or other undesirable symptoms related to questionable discs. At the very least, if you elect not to have the discs resurfaced, remove the glaze from the surface with emery cloth or sandpaper, using a swirling motion (see illustration).
5. It’s absolutely critical that the disc not be machined to a thickness under the specified minimum thickness. The minimum (or discard) thickness is cast or stamped into the inside of the disc (see illustration). The disc thickness can be checked with a micrometer (see illustration).
5a The minimum (discard) thickness of the brake disc is cast into the disc (rear disc shown, front similar)
5b Use a micrometer to measure disc thickness
Removal
Caution: On rear brake systems equipped with EPB (Electronic Parking Brake) the system needs to be deactivated before any work is performed on the rear brakes. Go to the general information section (see Electronic Parking Brake (EPB) – general information, troubleshooting, deactivation/activation and component replacement) for detailed instructions and procedures for deactivating the EPB system.
6. Remove the brake caliper as outlined in Disc brake caliper – removal and installation. It isn’t necessary to disconnect the brake hose. After removing the caliper bolts, suspend the caliper out of the way with a piece of wire (see illustration 5.3).
8. If equipped, remove the pressed-metal retaining washers and discard them (it is not necessary to reinstall them) (see illustration). Slide the brake disc off the hub or axle flange.
6.8 Use cutting pliers to remove any metal retaining washers from the wheel studs (if equipped)
Installation
9. Clean the mounting surface between the wheel studs. Remove any rust scale or debris that could interfere with the mating surfaces of the disc to the spindle.
10. Place the disc in position over the wheel studs.
11. Install the caliper mounting bracket, tightening the bolts to the torque value listed in this Chapter’s Specifications.
12. Install the caliper and tighten the bolts to the torque listed in this Chapter’s Specifications.
13. Install the wheel, then lower the vehicle to the ground. Tighten the lug nuts to the torque listed in the Tune-up and routine maintenance Specifications. Depress the brake pedal a few times to bring the brake pads into contact with the disc. Bleeding won’t be necessary unless the brake hose was disconnected from the caliper. Check the operation of the brakes carefully before driving the vehicle. Reactivate the EPB system (if equipped) by following the procedure in the electronic parking brake actuator section, (see Electronic Parking Brake (EPB) – general information, troubleshooting, deactivation/activation and component replacement) for detailed instructions.