Power Booster & Master Cylinder Question

[Keith Seymore]

Originally Posted by Captainfab

No you do not need a proportioning valve with drum/drums. The '67-'70 booster and master cylinder is what I recommend for use with a drum/drum system. That booster is compatible with my booster brackets also.

Sidebar: So if you don't use the proportioning valve with drum/drum, do you still get the safety aspect of a split system? Does the master cylinder reservoir provide protection in the event of a leak in either the front brake lines or in the rear lines, without the shuttle portion of the prop valve?

I am contemplating updating the single pot m/c in my '63 Grand Prix to a dual system, which is why I ask.

K

[Captainfab]

I am not aware of a proportioning valve for the drum/drum brake system. Of course most of my knowledge is with the trucks. The '67-'70 trucks use what I call a distribution block. It is basically 2 ports in, 2 ports out.

My '68 Camaro with drums/drums has a similar distribution valve

To answer your question, if either the front or rear circuit were to develop a leak, there is no shuttle to shut off flow to that side. But you should still have limited braking ability to the other side.

Originally Posted by Keith Seymore

Sidebar: So if you don't use the proportioning valve with drum/drum, do you still get the safety aspect of a split system? Does the master cylinder reservoir provide protection in the event of a leak in either the front brake lines or in the rear lines, without the shuttle portion of the prop valve?

I am contemplating updating the single pot m/c in my '63 Grand Prix to a dual system, which is why I ask.

K