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).
Continued memo on pedal operation, addressing issues with air in the system, oil contraction, and reports from Springfield.
| Identifier | ExFiles\Box 27\1\ Scan172 | |
| Date | 19th April 1929 guessed | |
| contd :- -2- back very much more quickly and with noise. In any case after one charge there is no reason to suppose the valve will open again as the vacuum beneath it is destroyed. That one charge of air will be forced out of the nearest drip plug after filling up and again operating the pedal, the head of the oil being enough to open the valve. In the event of an owner allowing the tank to become empty, we are advising him to operate his pedal twice, instead of once, until such time as it can be observed to stall directly after touching the dashboard. These two depressions will be given instead of one every 100 miles, and also when the chassis is at even temperature - in accordance with our usual instructions. The first stroke will go to the compression of the air, the second to the expulsion of oil through the drip plugs. With regard to air in the system, it is noticeable that although the plunger will stall immediately after touching the dashboard when the pipe lines are full and the oil is warm, if the chassis is allowed to stand and the oil cools off, the pedal will not stall for the first half inch or so. This is undoubtedly the effect of the contraction of the oil drawing in air through certain drip plugs and is hardly preventable. Springfield report that many of their cars seem to go through life with the pump pedal stalling an inch or so from the dashboard, and say that no trouble appears from this fact. contd :- | ||