(first posted 7/26/2011) One of the more obscure footnotes in automotive history is Chrysler’s premature fling with disc brakes, as fitted standard to the 1950 through 1954 Crown Imperial eight-passenger limousine. They were also a $400 ($3600 adjusted) option on other Chryslers, but that very stiff price and certain limitations with the unique Lambert-Ausco twin disc brakes meant few takers. Chrysler was ahead of the times, at least for passenger cars, because the Lambert-Ausco found another home as well, but it wasn’t a racing car like the first English Girling disc brake:
Yes, certain Farmalls also used the Lambert-Ausco. And good luck finding parts for them, Chrysler or International. These were something all-together different.
There were two discs with brake linings, inside a two-piece “drum”, and the discs expanded outward to make contact with those drums. Here’s an excerpt Richard Langworth: “The Complete History of Chrysler Corporation 1924 – 1985″
They were “self-energizing” in that some braking energy contributed to braking effort. When the disc make initial contact with the friction surface, small balls set into oval holes leading to the surface apart to augment braking energy. The effect was lighter pedal pressure than caliper discs, plus less fade, cooler running, and more friction surface than comparable drum brakes. Because of its high production cost, the all-disc system was standard only on the 1950 Town and Country and on Crown Imperials through 1954. It was a $400 option on other Chryslers, and thus rarely ordered. Current owners of cars so equipped consider the A-L brakes reliable and very powerful, but grabby and oversensitive.”
Chrysler reportedly used either too few cones and balls, or cones or balls that were not hard enough given the number used; they could deform under brake load, leading to brake failures.
What became the modern automotive disc brake was first conceived and built by that radical Frederick Lanchester in 1902, but the lack of suitable materials stymied the disc until 1953, when Girling discs were first available on the 1953 Jaguar C-Type. Even Mercedes used British Girling disc brakes.
The 1971 Imperial again was a pioneer, with a Bendix “Sure Brake” electronic anti-lock braking system, the first four-wheel ABS system offered on an American car (the 1966 Jensen Ferguson had the first in the world). Once again, its high price meant that it disappeared two years later. What goes around (the disc) comes around.