Technical report page detailing the performance and issues with a vehicle's braking system.
| Identifier | ExFiles\Box 7\7\ X 606 Brakes-page056 | |
| Date | 4th May 1937 | |
| -2- With only one rear brake disconnected, the car wanders over the road with the steering wheel free, goes straight if it is held lightly. Upon looking the front wheels the car dives to one side. We think the emergency brakes safer than on P.III. Detachable rear brake drums. The 10 number 1/4" dia. bolts cannot be replaced and split pinned up without shearing several of the bolts, or fiddling with washers. The operation would be easier if the bolt were slotted instead of the castellated nut, the nut drilled with 3 holes, not slots. The drum still runs true. Friction in the brake links. This is chiefly in the rear equalizer. We have asked for D.Sch.4924 to be altered, the 5/16" bolt in the slotted link to be replaced by a 1/2" bolt and the distance pieces strengthened to prevent compression. The jaw at the front end of the same Hand Brake pick up rod binds in certain positions. Hand Brake. This is pleasantly spongy and quite effective. It is possible to lock the rear wheels with it. We could not make it stick on by using the foot brake, as the drums are rigid. Strength. We have subjected the brakes to severe overloads but nothing has failed. The linkage is very rigid. Efficiency of Mechanism. We have taken a hysteresis loop of losses between pedal and one rear brake, the other being held off. The efficiency was very high, about 40% at 150 lb pedal load, no servo. Clanks. The only clank when the brakes are released comes from the servo reverse link. We had no air dash pot on the car. We are waiting to try the rubber stop. | ||
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).