The brakes on your car work through a system of hydraulics. When you press the brake pedal, it moves the master brake cylinder. The master cylinder, in turn, creates pressure on the system, which is trasferred to your brake calipers and discs by brake fluid in your car's brake lines and hoses. Because this is such an important safety feature on your car, the best way to repair a brake hose is by replacing it completely.
Park the car in a flat location. Put the car in park and set the parking brake. Turn off the engine and remove the keys from the ignition.
Place a block of wood or brick behind the rear wheel. Locate the jacking point nearest the brake hose that you want to replace. This information can be found in your owner's manual. Remove the hubcap on the wheel you are working on and loosen, but do not remove, the wheel's lug nuts. Slide the jack underneath the vehicle and raise the car up enough for you to work comfortably. Lock the jack.
Remove the lug nuts. Pull the wheel off the hub. Spray penetrating lubricant around the brake hose and allow it to soak in. Use the rag to wipe up any debris, dirt or gunk around or on the brake line.
Remove the brake line from the end of the hose located towards the front of the car. Most brake hoses have a hex coupling that attaches to the metal brake line. Use one wrench to hold the hex on the brake line steady while you loosen the hex on the brake hose with the other. This also prevents damage to the metal brake lines. Slip the plastic baggie over the end of the brake line and secure with the rubber band.
Loosen and remove the other end of the brake line located next to the wheel hub as you did the first end.
Connect one end of the brake line to the nipple outside the wheel hub. Tighten with the wrench.
Remove the plastic bag from the brake line. Thread the new brake hose into position. Tighten with the two wrenches.
Replace the tire. Tighten the lug nuts. Lower the jack and allow the car to rest on the ground. Remove the brick or block of wood from behind the wheel.
Bleed the brakes to equalize the pressure in the system and remove any air bubbles. Unscrew the bleeder screw at the rear of the wheel. Connect a bleeder hose to the screw and insert the other end into a jar filled with brake fluid. Have a friend pump the brakes until no more air bubbles flow out of the end of the hose. Tighten the bleeder screw. Repeat this process for all four wheels. Top up the brake fluid reservoir when finished.
