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 performance issues, axle control modifications, and petrol tank design flaws.
| Identifier | ExFiles\Box 83\1\ scan0253 | |
| Date | 12th August 1936 guessed | |
| ( I4 ) There was an occasional tendency towards excessive braking on the O.S.F. causing the car to pull into the gutter. Contraction crackles occurred as the drums cooled after every application however slight. This was due to uneven expansion of the liner and drum. They were very noticeable. The brakes were very constant in action and free from fading, and gave steady and dependable braking in emergencies. Brake squeaks were experienced during very heavy rain, although there was no evidence of water entering the drums. Squeals and groans also occurred on one occasion after driving 18 miles at 25 MPH, and then applying the brakes gently to stop. We attribute both these conditions to gentle application with cold drums, bringing out a squeaky characteristic in the linings. Brake thumps developed at 13.000 miles, these were reduced by attention to the swinging arm damper and rope slack, but soon became worse. It was found at 14.474 miles, that all the adjustment of the O.S.F. brake was used up, and it was necessary to let out the toggles in order to continue running. Examination showed that the O.S.F.linings were worn down to the rivets and that the brake drum liner was badly scored with grooves up to .020" deep. There were corresponding ridges on the linings. The N.S.F. and O.S.R. drums were fairly badly scored with grooves up to .007" deep. The N.S.R. drum was reasonably good with one deep groove. Wear occurred in the anti-judder weight pins and bearings. Squeaks became more frequent with the worn linings. No brake judders occurred during the mileage, but the anti-judder device does not sure thumping. AXLE CONTROLS. When the new brake plates were fitted at 5.343 miles, it was found that the lower bearings of the axle controls were slack. Modified axle controls were fitted at 9.080 miles, one of which was fitted with a spring to give the necessary end load on the lower bearing. These have not yet completed sufficient mileage to estimate their merit. PETROL TANK. LOP GB.374. Existing, complete to above LOP incorporating:- Lec.4859 Outside Filter. If the pump nozzle will not enter far enough, petrol is spilt out of the vents. Numerous pumps like this were encountered. The "Azur" petrol contains alcohol and has ruined the paint on the body side and wing where it has run down. It would be most unfortunate if one ran out of petrol and wanted to pour some in from a tin. Even an ordinary funnel would be no good. [Handwritten note in left margin, pointing to 'Contraction crackles'] G.W.H. Do we want to standardise these words [Handwritten note in left margin, next to the PETROL TANK section] Dixon This is unsatisfactory what about it? | ||