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).
The causes and potential remedies for brake squeaking and groaning on 20 HP and 40/50 models.
| Identifier | ExFiles\Box 5\3\ 03-page112 | |
| Date | 17th April 1925 | |
| EXPERIMENTAL REPORT -2- Expl. No. REF. Hsl/LG17.4.25. Known to be bad the worst offenders for squeaking are usually of this type. On the 20 HP. if the foot brake is squeaking the squeak can be eliminated if the side brake is put on lightly so that the shoes are in contact with the drum. Groans can also be cured by this method but more pressure is required on the brake shoes. We have tried changing the foot brake to the ~~opposite~~ outside of the drum. We believe this has reduced the tendency for squeaks but it has not eliminated them by any means. We have had a case in which the foot brakes squeaked and the side brakes squeaked but if the brakes were applied together the amount of squeaking was very greatly reduced. Squeaks occur on the 40/50, both on the rear and front brakes. On the 10,000 miles test we have usually had complaints of squeaky brakes. This most often occurred on the rear brakes and we usually find that the drum is scored badly. We have confirmed however that we can eliminate squeaking on the 40/50 HP. brakes if we damp the brake drums. We have tested several kinds of material including Ferodo, Halo (2 qualities) and Brasbestos. With all these materials we have had squeaks. It appears to be slightly less with some of the materials, but as an alround braking material, Ferodo is the most consistent and gives the longest life. Squeaks occur on brakes whether they are efficient or inefficient as regards braking. The squeaks originate from both the wrapping and non-wrapping shoes. We have tried contd :- | ||