[Tommy]

As for the line lock, are you referring to a line lock or a residual pressure valve? Residual pressure valves are used to maintain a small pressure in the line to keep the piston/pad from backing too far from the rotor. It's commonly used when the master cylinder is lower than the caliper. If you removed a residual pressure valve, you will have a larger than desired gap between the pad and rotor. This can result in the master cylinder running out of fluid before the pad is fully engaged with the rotor and, subsequently, reduced braking action.

Edited because I misread the earlier post.