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).
Brake performance, wear, and adjustments for car 11.B.V. with Hydraulic Front and Girling Rear brakes.
| Identifier | ExFiles\Box 121\1\ scan0235 | |
| Date | 23th January 1940 | |
| -3- Brakes on 11.B.V. Hydraulic Front, Girling Rear. When Lp.{Mr Lappin} first started running this car the brakes were coupled up direct, and were reported as having too much front braking, and also too much "lag" in operation between the servo acting in a forward and in a backward direction. The ratio of wear under these conditions was 5 front, 4 rear in notches. The braking system was altered to be the same as 30.G.7 and 33.G.7 when the speedometer was reading 6,726. During the following 1,700 miles we had two front brake failures due to a defect in one of the valve rubbers in the master cylinder, no further trouble has been experienced with the hydraulic part of the system. We show below a table of adjustment, since we fitted new rear shoes. Front Rear Speedometer reading n.s. o.s. n.s. o.s. 8467 1 1 2 2 notches 9309 0 0 2 5 9837 1 1 2 5 10570 0 0 1 5 10870 1 1 1 - 11694 At speedometer reading 11,694 we dismantled the O.S.R. brake to investigate the cause of the rapid wear. It was found that the Girling wedge was very sluggish in returning, and that the pins connecting the shoes were also on the tight side. The shoes and operating gear were dismantled cleaned and greased, another pair of shoes were fitted which were in an equally worn condition to the near side, which was checked and greased at the same time Since carrying out these repairs we have not adjusted the brakes, but a careful check will be made next time the car comes into the garage. From the figures we have shown it will be seen that the wear in notches is front 3, rear 8, which is very unequal. | ||