Brake line coil off master cylinder necessary?

[earl84]

I am redoing all my brake lines in conjunction with adding a Wilwood master and proportioning valve. Question is whether or not the coils are necessary or not that are generally right off the master.

I know GM did it on most stock trucks, but I see a lot of trucks without them. I want to do some different routing to clean things up a bit while I’m at it, and don’t really want to do the coils. If they are necessary, I assume thy should be horizontal instead of vertical so air can’t get trapped in the top part of the coil.