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).
Investigation report into the cause of rear brake squeaks, including a diagram of the brake shoes.
| Identifier | ExFiles\Box 32\2\ Scan041 | |
| Date | 28th April 1923 | |
| 40/50 x3458 REAR BRAKE SQUEAKS. Foot brake. Squeaks appear to come from off-side brake. Brake dismantled and examined. Top shoe worn most - bottom shoe fair and even. 1/3 of top shoe worn very badly on trailing edge. At X .070" more than rest of shoe. [Diagram of a brake drum with two brake shoes, labelled 'Shoe A' and 'Shoe B', and points 'X' and 'Y' marked on 'Shoe A'.] Shoes reversed - A being at bottom - B at top. On applying brakes on forward motion, there are no squeaks but squeaks are apparent on reversing when X again becomes trailing edge. Shoes replaced in original position and Ferodo strip at X (1/3 of surface). Taken off and allowing surface Y to bed more evenly. No squeaks either forward or reverse. When strip X is refitted and shoes are in original position, squeak again appears. Foot brake shoes taken off both sides and new shoes fitted and made to bed evenly. Quite O.K. Hand Brake. Very slight squeak both forward and reverse. Top shoe on off-side worn mostly, on trailing edge as on contd:- | ||