Hy oldieoldie, How large is the bore on the dual master cylinder you plan to use? I would not go smaller on the bore than the bore of the original master cylinder. Depending on whether your truck has Bendix or Wagner brakes, the connection at the rear wheel backing plate will be different. Yes there is a specific order to bleed the braking system with a Hydravac. Do you plan on installing two Hydravac's, one for each braking circuit, or will you install a vacuum booster in front of your new master cylinder?
