The leaks and external damage of metal lines and rubber brake hoses must be inspected regularly because, especially, it is possible to consider metal lines that can crush and kink under the vehicle and limit the flow of fluid and weaken the braking. Rubber hoses should be checked against cracking or scraping because this may cause weak spots, which might require failure during pressurizing. Where lines are pulled out or cut off great cleanliness is needed: the joints and connection must be cleaned prior to disassembly, and the lines and ports must be plugged directly after opening. Brake fluid should be sprayed into the new lines and hoses to cleanse them. In order to take out a line or hose, unplug the negative battery cable, lift and prop the vehicle and take out any wheel and tire assembly needed to do so. Wipe around the joints and have a catch pan on the ground then with two wrenches, disconnect the hose or line taking care not to use a decent one and leave a back-up wrench to avoid damaging the fittings. Retaining clips or brackets must be pulled off and in case brake system is kept open, tape or plug stuck some of the remaining clips and ports to ensure that nothing gets into them. To install, beginning with the one farthest away, both fittings should be threaded properly; the new line should not be rubbing against any other components, and a distance of at least 1/2 inch should exist between the steering column and moving components. Install all the fittings fully with two wrenches, replace any retaining clips or brackets, reassemble the wheel and tire packages, reassemble the vehicle to the ground, refill brake master cylinder reservoir with clean brake oil to DOT 3 specifications, bleed the brake system properly and reattach the negative battery cable.