While not specific to any particular vehicle, the information contained in the link below seems to cover the early V8 Bristols. It is included so that members may get a better understanding of how things work, and we thank Per Blomquist for sending it in.
Vacuum Screen washers
For those vehicles fitted with a vacuum washer system, the thick wall rubber tubing was not available from Bristol cars when last checked. Normal clear plastic tubing does not appear to have the residual strength, especially when warm, to support a vacuum. One source is Stevenson’s Motors Tel: 0121 472 – 1702.