The following contact information may prove helpful for folks with the vacuum powered disc brake trailers: Ausco Products, Inc.2245 Pipestone RoadBenton Harbor, MI 49022800 253-2860This is the manufacturer of the caliper. It is a style 2.Caliper # 28639. The part numbers in the Airstream manual are, by in large, still good. Ausco can send you an engineering drawing, too.Ausco doesn't sell direct. Berendsen Fluid Power14565 Valley View Ste. BSanta Fe Springs, CA 90670562 921-3335The hub rotor assembly was Kelsey-Hayes and is no longer made. I haven't tried to track down the bendix hydrovac unit yet, but it is used in industrial applications and it should be possible to get repair parts.
I have installed the Ausco power unit. It works great. The company sent out notices a while back that the units were going to be discontinued. A guy named Mark was a contact name.
The unit is a 12 volt
electric motor that makes a piston operate the hydraulics for the discs. There are also units for drum brakes. With the Ausco unit, there is NO vacuum connections.. I have old vac unit for parts...... Frank