66-67 Dodge Charger Source Guide

Master Cylinder Upgrade

Posted by: John Paseman on 06/05/03
If your only change is the MC and you have drum brakes, the only extras you need are a plug, a new line and a coupler.

The orig MC had one line that went to a distribution block. From there, one line went to the rear, one to the left front and one to the right front.

With the new Dual MC, hook the orig line to the front brake circuit (usually the rear cylinder of the MC). Remove the orig rear line from the distribution block and plug the hole in the block. This distribution block is now for the fronts only (left & Right). Now make a new line to extend from the old rear line to the new MC (Use the coupler to connect the old line to the new extension line). Connect the other end of the new extension line to the rear circuit of the new MC and you should be golden.

If you have discs, you might need a proportioning valve in the rear line. There used to be a thing called a residual valve also, but most brake kits include expanders, so if your brakes have been done in the last 20 years, you probably no longer need the residual vale either, since the expanders (little spring things in the rear brake cylinders) keep a little pressure on the cylinder, hence no need for the orig type 2 lb residual valve (to keep a little pressure).

Brakes are a pretty gripping subject - yes?

If you want to change from the heavy Cast Iron MC to one of the new aluminum masters (two stud mounting), I have the adapter plates on my web site at ww.UsCarTool.com