It was in the early 1920s when the prestigious carmaker Pierce-Arrow Motor Car Company added a vacuum assist to its brake systems, making them the first cars with a brake booster. Your 2005 Ford Expedition has come a long way from those early days. If you've driven a car with manual brakes -- and not many people around today have -- you have an appreciation for the power brakes that come standard on nearly every car sold in the U.S.
Open the hood and allow the engine to cool, if necessary. Install a memory-saver device according to the manufacturer's procedure.
Loosen the negative battery cable terminal clamp nut, using a ratchet and socket. Rotate the terminal slightly on the post to help break it loose, then remove the terminal from the negative battery post. Route the loose cable away from the battery to prevent accidental contact.
Locate the air cleaner housing and air cleaner outlet tube. Loosen the air cleaner outlet tube hose clamp, using a nut-driver. Disconnect the MAF sensor electrical connector, then lift the air cleaner housing up and out of the engine compartment.
Using a ratchet and Allen driver, remove the power steering fluid reservoir retainer screws, and carefully move the reservoir aside to gain clearance for the booster removal.
Locate the brake fluid level sensor on top of the brake master cylinder, and disconnect the electrical connector. Disconnect the brake pressure switch wire from the bottom of the master cylinder, if applicable.
Using a ratchet and socket, remove the master cylinder mounting nuts, then discard the nuts. Slide the master cylinder off the mounting studs, and move it aside to gain clearance for the brake booster, without kinking any of the lines. Support the master cylinder with a wire or bungee cord so there is no strain on the brake lines or fittings.
Remove the two mounting bolts from the cooling system degas bottle, then position it to gain clearance for the booster.
Squeeze the tabs on the vacuum hose clamp, using pliers, then remove the vacuum hose from the hose barb on the booster. Remove the pedal travel sensor and booster solenoid wires, if applicable.
Working inside the passenger compartment, remove the brake linkage cotter pin, then slide the washer, bushing, switch and the pushrod end off the brake pedal stud.
Peel down the carpeting around the booster pushrod to access the booster retainer nuts. Remove the four retainer nuts, using a ratchet and socket. Lift the booster out of the engine compartment.
Move the new booster into position while threading the four mounting studs, and the booster pushrod, through the holes in the firewall. Install the retainer nuts and torque them to 16 foot-pounds, using a foot-pound torque wrench and socket.
Install the booster pushrod, washer, bushing and switch on the brake pedal stud, then install the cotter pin. Move the carpeting back into position over the booster retainer nuts.
Install the booster vacuum hose and hose clamp, then tighten the clamp securely. Install the pedal travel sensor and booster solenoid wires, if applicable. Install the engine cooling system degas bottle. Install the retainer bolts and torque them to 80 inch-pounds.
Install the master cylinder on the mounting studs. Install and torque the new retainer nuts to 16 foot-pounds. Install the brake level switch wire, and the brake pressure switch wire, if applicable.
Install the power steering fluid reservoir and retainer screws. Torque the screws to 8 foot-pounds. Install the air cleaner assembly. Install the air cleaner outlet tube and tighten the clamp securely. Install the MAF sensor connector.
Install the negative battery cable terminal on the negative battery post. Torque the terminal clamp nut to 44 inch-pounds. Remove the memory-saver.
