This seems like a chance to get a dumb question answered. (I am not looking to change to a dual master cylinder because my 66 GMC 5500 truck uses a tandem master cylinder for brakes and clutch that, as far as I know, does not come in a dual configuration for brakes.) But I have still wondered how a dual master cylinder would connect to a hydrovac that has only one brake line inlet and outlet. One of the major advantages of the dual master cylinder is not losing both front and rear brakes at the same time because of a big leak, such as failure of one of the rubber hoses, and this advantage would be lost at the hydrovac because it has only a single outlet connecting to both front and rear brakes. Is this correct? How do more modern trucks, that I assume are required to have dual master cylinders, deal with this?
