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).
Seizure of the brake mechanism on Bentley 3 1/2 & 4 1/4 Litre chassis, and suggesting modifications.
| Identifier | ExFiles\Box 102\6\ scan0161 | |
| Date | 5th January 1938 | |
| To Bentley Motors Ltd. Derby........... Copy to .......... Rm{William Robotham - Chief Engineer}/AEM. Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} Br.{T. E. Bellringer - Repair Manager} is absent Levallois Re: SEIZURE OF BRAKE MECHANISM ON BENTLEY 3 1/2 & 4 1/4 LITRE CHASSIS. ------------------------------- With reference to Rm{William Robotham - Chief Engineer}5/R.15.5.37 and Agenda attached to it, Item 4 "Accessibility and cost of Service", we give below our remarks and some suggestions re modifications which we think could with advantage be carried out to the brake mechanism on Bentley 3 1/2 and 4 1/4 litre chassis. REAR BRAKE MECHANISM. We think that a certain amount of time could be saved when dismantling and re-erecting the rear brake shoes if some minor modifications were carried out to the brake mechanism. The above operation is rendered much more difficult when the pins of the toggle forks are found to be seized in the shoes and also when the brake shoes are found to be seized on to the GB.2021 bush which passes through the pivot of the brake shoes. This condition frequently arises. We find that the fitting of the cadmium plated steel bushes and end washers as per Depot sheet N°323 has not had the desired effect. There is no doubt that, on certain series of chassis, far too much water and mud finds its way past the brake drums which, in the end, causes seizure or partial seizure of the moving parts and corrosion of the aluminium shoes, and it is this which often makes the brake re-lining job more expensive than it should be. When we attend to rear brakes for re-lining or other purposes necessitating the removal of the shoes, we find it necessary, should the brake mechanism be found in the condition described above, to dismantle the dust cover to avoid deforming it. The removal of the dust covers is not an easy job with the rear axle in position. In order to avoid if possible the aluminium corrosion effect which takes place between the pivoted portion of the brake shoes and the external diameter of the GB.2021 bush (steel cadmium plated), we suggest that small (thin) rolled split bronze bushes as per attached sketch might be fitted to each brake shoe so as to insulate the aluminium from the cadmium plated bush. In order to facilitate dismantling and erecting, we also suggest that the GB.2021 | ||