How to Make Hard Brake Lines

Hard brake lines are standard equipment on passenger cars, trucks and trailers. The lines, made from galvanized steel tubing, carry brake fluid from the master cylinder to the brake differential and the front and rear brakes. While making brake lines is not particularly difficult, you must guarantee that the pair of lines from the master cylinder to the brake differential are of equal length to ensure even braking. You can make hard brake lines using the appropriate size tubing and fittings for the brake system found on your car, truck or trailer.

Instructions

1

Measure the length of an existing or damaged hard brake line that connects between the master cylinder and brake differential. If a new line is needed, measure the distance from the appropriate master cylinder fitting to the appropriate brake differential fitting and add 16 inches to allow for configuring the necessary bends.

2

Cut a section of galvanized steel brake line to your dimension using a tubing cutter. The line will be sized to the exact length after it has been configured.

3

Make an "S" bend (two-way bend) near one end of the line using a tubing bender. Allow the end of the line to extend past the front of the bend enough to make a straight-on connection at the brake differential.

4

Slide a compression fitting on the end of the straight section near the two-way bend, making sure the threads of the fitting face the fitting on the brake differential. Flare the end of the line at the straight section using a flaring tool.

5

Slide the fitting against the flared end of the line. Thread the fitting into the appropriate port on the brake differential by hand. The fitting will be tightened later.

6

Establish the degree of bend that is needed at the upper section of the line to make a straight-on connection to the appropriate fitting on the master cylinder. Mark the point where the bend is needed.

7

Loosen and remove the lower fitting from the brake differential by hand. Bend the brake line at your mark using the tubing bender.

8

Thread the lower fitting onto the brake differential by hand. Determine whether the upper bend needs to be tweaked to allow a straight-on connection. Remove the line and make the final adjustment using the tubing bender.

9

Reattach the lower fitting to the brake differential by hand. Mark the point where the upper end of the line is cut to length at the master cylinder. Loosen the lower fitting. Remove the line and cut it at your mark with the tubing cutter.

10

Slide the upper compression fitting onto the line, making sure the fitting is facing correctly to attach to the master cylinder. Flare the end of the line using the flaring tool. Attach the brake line fittings at the brake differential and master cylinder. Tighten the compression fittings using an open-end wrench.