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 system and front hub performance, detailing issues and modifications.
| Identifier | ExFiles\Box 82\5\ scan0159 | |
| Date | 2nd June 1937 guessed | |
| ( 8 ) FRONT HUBS. LOP. GB.2398. GB.1988 Chromidium Brake Drums. SERVO MOTOR MECHANISM. LOP. GB.1908. Hs.{Lord Ernest Hives - Chair}1631, I589. N.S.3971 - 4453. Lightened Servo - 35° cams. There was a tendency to lock the rear wheels with medium pedal pressure throughout the mileage. This caused excessive overheating and wear of the rear brake linings. The S.3805 material suffered badly under these conditions on the rear brakes, and very severe groans, squeaks and picking-up on the drums occurred. On the front brakes, which did not become unduly hot, no trouble with the S.3805 was experienced. It has also proved satisfactory on 35-EX. Phantom III, apart from a slight tendency towards squeaks. The front braking was increased by bringing the front equalizer shaft up to standard specification, errors in the levers having been found. After fitting the B.Z. liners and chromidium rear drums with increased cooling, excessive wear of the rear brakes continued but no further groans occurred, and the rear liners and drums remained in very much better condition than with the S.3805. No squeaks occurred with the B.Z. liners. The excessive rear braking was subsequently attributed to partial seizure of the servo spindle. This could not have been correctly packed with grease when assembled. Excessive slack developed in the pins and bushes of the anti-judder weights. REAR BRAKES. LOP. GB.854. The following new scheme incorporated:- GL.{G. Linnett}833 Mod. lubrication of rear brake Actuating Shafts. GB.2419/20 Actuating shafts - Hand Brake. GB.2421/22 Actuating shafts - Foot Brake. Z.S.2 & Z.T.2 Bijur feed replaced by Z.S.1 & Z.T.1 after 2.000 miles. Excess oil was entering the brake drums with the size 2 feeds. After replacing them by size I, no further excess entered the brakes. The lubrication of the shafts was satisfactory. [Handwritten text on the left margin] Martindale Have we ever fitted S 3805 - to a Customers Car Yes on Alum drums. no complaints. | ||