Brake hydraulic system — bleeding Ford F150
Warning: Wear eye protection when bleeding the brake system. If the fluid comes in contact with your eyes, immediately rinse them with water and seek medical attention.
Warning: Brake fluid that has been sitting around for a long time should not be used. Purchase new brake fluid instead. Brake fluid is hygroscopic and aborbs moisture from the air, which can cause the fluid to boil under heavy braking conditions, which will render the brakes useless. If the brake fluid is old or has been left unsealed, it should be disposed of properly; it is unsafe for use.
Note: Bleeding the brake system is necessary to remove any air that’s trapped in the system when it’s opened during removal and installation of a hose, line, caliper, wheel cylinder or master cylinder.
1. It will probably be necessary to bleed the system at all four brakes if air has entered the system due to low fluid level, or if the brake lines have been disconnected at the master cylinder.
2. If a brake line was disconnected only at a wheel, then only that caliper must be bled.
3. If a brake line is disconnected at a fitting located between the master cylinder and any of the brakes, that part of the system served by the disconnected line must be bled.
4. Remove any residual vacuum from the brake power booster by applying the brake several times with the engine off.
5. Remove the master cylinder reservoir cap and fill the reservoir with brake fluid. Reinstall the cap.
Caution: Check the fluid level often during the bleeding operation and add fluid as necessary to prevent the fluid level from falling low enough to allow air bubbles into the master cylinder.
6. Have an assistant on hand, as well as a supply of new brake fluid, an empty clear plastic container, a length of plastic, rubber or vinyl tubing to fit over the bleeder valve and a wrench to open and close the bleeder valve.
7. Beginning at the right rear wheel (the longest brake line from the master cylinder), loosen the bleeder screw slightly, then tighten it to a point where it’s snug but can still be loosened quickly and easily.
8. Place one end of the tubing over the bleeder screw fitting and submerge the other end in brake fluid in the container (see illustration).
11.8 When bleeding the brakes, a hose is connected to the bleed screw at the caliper and submerged in brake fluid -air will be seen as bubbles in the tube and container (all air must be expelled before moving to the next wheel)
9. Have the assistant slowly depress the brake pedal and hold it in the depressed position.
10. While the pedal is held depressed, open the bleeder screw just enough to allow a flow of fluid to leave the valve. Watch for air bubbles to exit the submerged end of the tube. When the fluid flow slows, tighten the screw, then have your assistant release the pedal. Caution: The assistant must not release the brake pedal with the bleeder screw open or air will be sucked back into the line.
11. Repeat until no more air is seen leaving
the tube, then tighten the bleeder screw and
proceed to the left rear wheel, the right front wheel and the left front wheel, in that order, and perform the same procedure. Be sure to check the fluid level in the master cylinder reservoir frequently.
Models with EPB (Electronic Parking Brake)
12. Apply and release the parking brake five times.
13. Starting with the right-rear caliper, place one end of the tubing over the bleeder screw fitting and submerge the other end in brake fluid in the container. Loosen the bleeder screw 1/2 turn until no air bubbles exit the caliper.
14. Repeat Steps 12 and 13 as necessary, then perform the same procedure on the left rear caliper.
All models
15. Refill the master cylinder with fluid at the end of the operation.
16. Check the operation of the brakes. The pedal should feel solid when depressed, with no sponginess. If necessary, repeat the entire process.
Warning: If you are in doubt about the effectiveness of the brake system, or the BRAKE • or ABS light is on, DO NOT OPERATE THE VEHICLE. Have the vehicle towed to a dealer service department or qualified independent repair shop for further testing.