[There is no proportion to it just a place to run all 5 lines/QUOTE]
My Scarebird disc brake installation in a lightweight 65 Dart with dual master cyl was done without a proportioning valve; it's function being to reduce/delay the rear brake pressure to avoid lockup of the rear wheels prematurely.
The thinking was that the tiny 9 inch rear drums had measureably less capacity then the front discs thus providing a "proportioning" of brake capacity to the light rear & heavy front.
As a test studded snow tires were mounted front & rear and the brakes slammed on. Grooves in the pavement were identical length for both the front & rear tires....it seemed they might be well balanced.
I was concerned that a proportioning valve could have the effect of lengthening the stopping distance for a disc brake/9 inch drum combo.
Perhaps a heavier 70's Dart with 10 inch rear drums might have different results & need a proportioning valve?
