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).
Notes for a private owner on how to undertake Girling brake adjustments.
| Identifier | ExFiles\Box 160\5\ scan0305 | |
| Date | 7th March 1941 | |
| 220 BP The Autocar March 7th, 1941 BRAKE ADJUSTMENT Notes on Jobs Which the Private Owner Might Undertake for Himself No. 1. THE GIRLING NOW that it becomes increasingly difficult to get work done on cars by service stations owing to the occupation of labour elsewhere, the private owner is obliged to fall back upon his own resources. Owing to the current fashions in cars, not only in shape, but in construction, accessibility is not what it used to be, as seen by the private owner. Without a proper pit or a ramp, even running adjustments are apt to be decidedly difficult. Even so, we are lucky in one respect. Modern braking systems are fairly trouble-free, and the chief cause for attention is the "fair wear and tear" on brake linings. Linkage systems are not apt to get out of order, and are usually best left alone, except for lubrication, or topping-up and "bleeding" in the case of hydraulic systems. To keep brakes in good condition, therefore, periodic attention to the adjustment provided for the expanding shoes is usually all that is necessary, and this is well within the scope of the owner if approached with common sense. Again, if brake linings are so much worn that further adjustment is unavailing, the owner can still do something about it for himself if the service station is unable to help. Spare shoes, or relined shoes, are still more easily obtained from existing stocks than is the labour to replace them. The relining of old shoes is rather beyond the scope of an owner who is not something of a mechanic. * * * GIRLING BRAKES From an historical aspect there can be no doubt that the advent of Girling brakes some years ago had an immense influence upon the development of brakes generally. The Girling set up a new standard of efficiency in braking, and at the same time reduced the need for adjustment to a minimum, besides rendering adjustment itself a very easy and simple matter wherein even the need to jack up the wheels was eliminated. These brakes are self-aligning, fully compensated, possessed of a very high efficiency in the expander mechanism, and of almost frictionless operation of the straight-pull linkage or "hook-up" system. As a result of their many virtues Girling brakes are standardised on a wide variety of fine British-built cars, including Austin, Autovia, Aston Martin, Armstrong Siddeley, Beardmore, Daimler, E.R.A., Ford, Lanchester, Lea-Francis, Morgan, Napier, Riley, Rover, S.S. and Singer Bantam. Recently, to put the hallmark on a remarkable record of success, the Girling brake expander and adjuster systems have been adopted by Rolls-Royce, Ltd. upon that last word in superfine fast cars, the new Bentley Mark V.{VIENNA} Before describing how to adjust Girling brakes it is necessary to explain the principles. Each brake consists of a pair of shoes anchored at a fulcrum point, where the adjustment is situated, and at the diametrically opposite point is opened apart by an expander mechanism which is one of the particular features of the design. Carried by the backplate is a die-cast housing in which an inverted hardened cone or wedge can be drawn inwards, towards the centre of the car, by a jointed pull-rod enclosed in a dirt-excluding rubber “concertina.” Roller-bearing Wedge At right angles to the operating path of this wedge, as seen in plan view, there is on each side within the housing a sliding plunger, having its outer end slotted to engage the extremity of the brake shoe. The inner face of each plunger is inclined at an angle to match that of the wedge, and between these two faces a hardened-steel roller is interposed. Thus a roller-bearing wedge is obtained. It is a special point of the design that the two rollers are free, and can therefore roll on the wedge and on the inclined face of each plunger. There is no rubbing movement, only rolling. This ensures light action with minimum friction, and also makes it possible to employ a high step-up ratio, 6.3 to 1, and thereby reduces the load otherwise necessary on the pull-rod mechanism. Retaining pins in slots at the sides of the two plungers prevent them from moving out of the housing if the shoes are taken off. This expander assembly is packed with Duckham's Keenol grease—that nice Image Captions and Labels: Center Image Caption: The complete drum assembly, showing in perspective (top) the expander and (bottom) the expander adjustment. Bottom Left Diagram Caption: Details of the adjuster unit. Bottom Left Diagram Labels: SET PINS, ADJUSTABLE SPINDLE, STEEL HOUSING, PLUNGER, HARD STEEL CONE, FLAT, PLUNGER. Bottom Right Diagram Caption: The expander unit in detail. Bottom Right Diagram Labels: PULL ROD, DOUBLE COIL SPRING WASHERS, CLEARANCE SLOT, DIE CAST HOUSING, PLUNGER, FREE ROLLERS, WEDGE, PLUNGER. | ||