The Layout of Shoes and Springs in the Regis Bendix brakes.
The view to the left shows the layout of the front offside (Right hand) brake. The nearside is a mirror image and the rear brakes are the same layout as the respective front brakes except that they are at a different angle to allow easy entry of the brake operating cable. This puts the adjuster/anchorage line on the horizontal plane. Photo: P E Caunt.
The view left shows the layout of shoes, springs and adjusters for the rear offside of the car. The nearside is a mirror image of this side and the front brakes are the same layout as the rears except that the backplate is turned through 90 degrees so that the cable enters the backplate at a convenient angle. The front brakes, therefore, have the adjuster at the top. (As seen in the top view.)
The Bendix system used on the Crossley Regis is the single anchor type which followed the double anchor type used on the larger Two and Three Litre cars. Both types work in a similar fashion being known as “double servo brakes”. The servo action is from the wheel rotation effect on the primary shoe which then pushes against the secondary shoe thus providing “double” servo effect.
The Crossley Register Newsletter has published Practical Motorist articles in CRN 55 on pages 46 and 47 showing the layout of the shoes and springs and also the adjustment of these brakes. Unfortunately, these articles, dated 1955 and 1956 contain some errors. A drawing showing the layout of brake shoes and springs – but hardly mentioning the operating levers – indicates the wrong direction of rotation of the wheel. The drawing shows the front nearside wheel but direction of wheel rotation should be anti-clockwise, not clockwise. The article that gives great detail in explaining the different adjusting methods is correct except that it does not actually show the vital springs and operating levers.
Basically, the brakes have two shoes that are designated “Primary” and “Secondary” These are connected by four springs and the operating levers are connected to the operating cable and the primary shoe. The four springs are as follows:
1 Secondary shoe to anchor pin..
2 Primary shoe to Anchor pin.
3 Actuating cam to adjuster end of Primary shoe.
4 Primary shoe to Secondary shoe across the adjuster ends. (Holds the shoes into the adjuster).
NOTE: The spring No.2 should be stronger than spring No.1. This allows the Primary shoe to operate before the Secondary shoe as mentioned above. If you are lucky enough to have original springs in good condition, then the No 2 spring will be painted black and No.1 will be red for identification purposes.
Lastly, two small springs in cups fit into the backplate and the ends of these springs locate in the middle of the shoe webs to hold the shoes against the backplate.
For no apparent reason, the web of the Primary shoe is narrower than that on the Secondary shoe. I know of no reason for this but suggest this shoe be fitted as the Primary.
The Secondary shoe can be positively identified by the fact that the shoe web covers the operating lever that is attached to the brake operating cable. The other end of the two-piece operating lever (actuating cam) is attached to the Primary shoe close to the adjuster end of the shoe.
The Primary shoe is the shoe to the rear of the drum in relation to the direction of travel. For example, the front nearside drum will have the primary shoe to the right when looking at the backplate from the side of the car. However, when the car changes direction – reverses – the primary shoe becomes the left shoe since the car is then moving the opposite way. However, because the springs remain unchanged, the servo action is reduced which is one of the reasons for Bendix brakes having a reputation for being relatively poor in reverse compared to forward running. Another reason is that some casting lines on the operating levers prevent the smooth action of the brake in reverse and should be filed off when preparing the brakes for operation. This will improve the brakes for both directions.
The notes concerning operation of Bendix brakes all agree that no alterations to the cables should be made to take up wear. All adjustments should be made using the adjuster within the backplate of each wheel and cables only adjusted to ensure that they start to operate at the same time to ensure equal operation on each wheel.
When the braking system has been set up, it is stated that 6,000 miles can be achieved without adjustment being necessary. I would suggest that this may well be less when the car is used in modern traffic conditions where the more casual braking of earlier years is no longer an option.
The brake cross-shaft from which the cables originate is under the dash area on the chassis. The cables, therefore, go forward or backwards to the brake backplates. The front backplates have the adjuster at the top and the anchor pin at the bottom with the brake cable entering the backplate at the – roughly – 10 o’clock (F/N) and 2.o’clock (F/O) position. On the rear axle, the backplates are fitted with the adjuster in the horizontal plane towards the front of the car and the anchor to the rear. The cable enters at the 8 o’clock (R/N) and 4 o’clock (R/O) position and provides the same servo effort as at the front wheels.
Before adjustment can be achieved, the brakes must be set up. This is necessary usually, only if the anchor pin has been loosened or removed for repair work. Assemble the brakes by fitting the anchor pin and bolting it up very tight. The adjuster wheel that has the squared end sticking through the backplate to the outside of the drum should be in place and a spring clip fitted into the slot in the square shaft to locate it and stop it falling into the drum interior. Snail adjusters (eccentrics) that bear on the shoes can be fitted and turned to their lowest position until needed. The brake cable is fitted and the brass fitting bolted to the backplate with the bolt and spring washer into the threaded hole in the backplate. The operating levers (one is referred to as the “actuating cam” in some instructions) are fitted to the anchor pin and the cable fitted to the operating lever. The two shoes can be placed on the backplate and the anchor springs used to hold them in place. The domed spring top fits into the hole in the backplate and the other end of the spring locates in a hole in the shoe web. The rounded ends of the shoes fit on the anchor pin whilst the other, squared off slotted ends fit into the adjuster ends. A spring fits into the end holes of the two shoes across the adjuster and holds the shoes in place. The main springs fit as listed above, remembering that the secondary shoe has the stronger black spring.
To adjust the eccentric adjuster, revolve the wheel until the inspection slot in the drum is one inch from the adjusting screw end of the lining of the secondary shoe. Insert a 0.008 inch feeler gauge at this point and turn the eccentric in the direction the wheel revolves until the lining grips the feeler, then lock the eccentric. Next try a 0.008 inch feeler gauge at a point one and a half inches from the anchor pin end of the top shoe. If this is not approximately correct, adjust the anchor pin as detailed below.
The adjusters are arranged so that they can be tightened by turning towards the front of the car. ie: Nearside turned anti-clockwise and offside turned clockwise. (Since this depends on which way the adjuster is fitted, the turn of the adjuster can be changed to suit your own requirements!)
If the anchor pin needs to be re-set, tighten the adjuster until the wheel can hardly be turned. Slacken off the anchor pin nut and tap with a soft hammer. This will allow it to centralise and the nut should then be tightened. Then repeat the adjustment of the eccentrics as described above. Tighten the adjusters until the front wheels are locked and the rear wheels can just be turned. The cables can now be adjusted for length so that the clevis pins can be fitted with the cables tight. Slacken off the adjusters and check that the wheels are free to rotate (slight resistance is acceptable) and the brakes should be ready for use.
If new brake cables are required, Speedograph-Richfield of Nottingham, UK can make new cables using the old items as pattern or to your drawing giving the appropriate dimensions. Note that the new cables will have a three inch long screwed end to fit in the yoke that is fastened to the brake cross shaft. This will need to be cut to length prior to fitting and is supplied long to allow maximum adjustment since the cable will stretch over time. A certificate is supplied by Speedograph-Richfield showing the load to which the cables have been tested.
Acknowledgements are also due to Ron Barton and the Library of his enthusiast friend, the late Adrian Townley for providing information from The Autocar Handbook, Motor Car Maintenance, Overhaul and Repair and Practical Automobile Engineering. The CRN notes from Practical Motorist and Motorcyclist, originally included in CRN 55 by Malcolm Jenner are also referred to in this article.