Brake Line Replacement
If the brake line is rusty or damaged, replace the entire length of line with one that's approved by the vehicle's manufacturer (steel line) not copper or a compression fitting. Copper lines can rupture from pressure, and copper fittings can leak. A good visual inspection typically reveals the problem.
When a restriction forms in a brake line, the master cylinder creates more than enough pressure to bypass the kink and apply the brake. The problem is the brake caliper or wheel cylinder is unable to generate enough force to bypass the restriction and return the fluid to the master cylinder.
This extra pressure keeps the brake applied. A kink in the LF front brake line will cause a pull to the left. Use caution while inspecting this unit though; brake friction causes a considerable amount of heat.