Re: Brakes

Posted by Owen_Dyneto On 2007/11/27 14:42:26

The actuation of the TreadleVac vacuum system follows the pattern of the earlier Bragg-Kliesrath (later bought by Bendix) system used on senior Packard Eights, Super Eights and Twelves from 1933 thru 1939, whether on the mechanical system (thru 1936) or the hydraulic system. These systems were pretty much bullet-proof as many still work today 70+ years later with little or so service required. A similar B-K system was used on many heavy duty over-the-road trucks thru the 50s and perhaps even later. In these sytems, vacuum is held in reserve in a vacuum storage tank, and when the brake pedal is actuated the vacuum enters the chamber of the booster. I believe the distinction you're thinking of is that in most modern units of later design, the vacuum reserve tank is actually part of the booster body.