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).
Outlining the 10,000-mile test procedure for hydraulic shock dampers, focusing on breather function and oil loss.
| Identifier | ExFiles\Box 55\3\ Scan200 | |
| Date | 15th June 1926 | |
| /235 To GWH. {George W. Hancock - Head Chateauroux} from Hs {Lord Ernest Hives - Chair} /Rm. {William Robotham - Chief Engineer} Hs {Lord Ernest Hives - Chair} /Rml/LG15. 6. 26. HYDRAULIC SHOCK DAMPERS. X235 10,000 MILES TEST. x7940 We are anxious to know whether a breather is necessary on these shock dampers. We have therefore blocked up the breather on one of the front shock dampers, while leaving it open on the other one. We should like you to observe whether there is any difference in the oil retaining qualities when the breather is blocked up. We should like to know exactly how much oil is lost from these dampers. We suggest that after the run down to Chateauroux, the caps are removed from the shock dampers and the oil level adjusted up to the top of the filling plug. The exact level of this level should then be measured with a depth gauge or a rule. It is necessary to always measure the height of the oil in the shock damper at the same atmospheric temperature, otherwise, the oil is likely to expand and contract and raise or lower the level. If the readings are taken at night however, the temperature should be substantially constant. We should like some indication of how much oil has been lost after each 1000 miles running in inches or fractions of an inch that the oil level has fallen. We are particularly anxious that the shock dampers should run the full 10,000 miles without requiring replacement. We should therefore like you to refrain from re-filling them as long as their efficiency remains unimpaired. contd :- | ||