From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Troubleshooting guide for a gauge, detailing issues such as wet or leaking air lines.
| Identifier | ExFiles\Box 26\2\ Scan316 | |
| Date | 17th May 1929 guessed | |
| contd :- -3- standing. It should only be necessary to use the hand pump when the car has been standing or the gauge has been disconnected for some reason or other. Under these conditions a few strokes of the hand pump will ensure the correct reading without the car having to be taken on the road. The troubles which can beset this gauge are : (1) A wet air line. This is almost unknown except when an installation is first assembled or has to be dismantled for any reason. It is due to a bead of petrol or water getting in the fine bore pipe between the tank and the dashboard. When this bead is in the pipe it obviously obstructs the transmission of pressure and so the gauge behaves erratically. The notes on correction clearly state how this trouble can be overcome and the line cleared. If a gauge is working erratically this process should always be carried out. Other causes of a wet line are breakage of the glass in the gauge head or a fracture in the piping but these troubles are practically non-existent. (2) Leak in the air line. This can be detected by a rapid drop in the gauge reading when it has been brought to the correct level by means of the hand pump and been allowed to stand for a short time. The air line should be checked separately as explained in the notes and if O.K. the unions should be suspected. contd :- | ||