What does it take to stop a 1950s, four-ton limousine that just so happens to be carrying the leader of the free world? If you answered “good brakes,” you’d be right. And, there’s quite a story behind the brakes on the Chrysler limousine used by president Dwight (Ike) Eisenhower. You might say that Ike’s preference for Chryslers had a profound effect on the design of automotive brakes throughout the World.
Ike preferred Chryslers
Back in January of 1953, Dwight D. Eisenhower was sworn into office as the 34th President of the United States. Though a fully-outfitted 1950 Lincoln Cosmopolitan limousine was available for his use (courtesy of the Truman administration), Ike preferred Chrysler automobiles. In fact, as a private citizen, he owned quite a number of them, including 1948, 1950 and 1952 models.
According to records, upon Ike’s request, Chrysler built two presidential limos for his administration. Both of the cars were over 25 feet long and due to bulletproof shielding and other bulky modifications, each weighed over 8000 pounds. This presented some unique challenges. Getting the limousines to move rapidly wasn’t a problem as each was outfitted with a 331-cubic-inch Firepower HEMI V-8, but stopping them was another matter. The bottom line was that it was not prudent to outfit such a heavy vehicle, especially one carrying the President of the United States, with the ordinary “drum-style brakes” of the day. As a result, Chrysler needed to find an alternative.
Drum-style brakes
Up until Ike’s administration, the standard technology used to stop automobiles and trucks was a design called “drum brakes.” As the name implies, drum brakes incorporate a large metal drums. Thanks to Brown’s Chrysler of Patchogue, a local Chrysler, Dodge, Jeep, Ram dealer in Patchoque, NY, we can explain how they work:
When the brakes are applied, inside the drum a pair of curved, asbestos-lined brake shoes expanded outward and are squeezed against the spinning drum and wheel. The resulting friction from this process slows down the rotating wheels thus bringing the vehicle to a stop. There was a problem, though. Drum brakes are built as enclosed systems and during heavy use they can trap superheated air. This will often lead to dangerous overheating of the metal brake components and can cause braking failure, especially with heavy vehicles – like 8000 lb limousines.
A new system
It’s a fact that advanced braking systems were, and still are, a priority at Chrysler Corporation. In fact, even back in 1920s, Chrysler was leading most of the American car manufacturers in braking technology. Here’s just one example of their leadership in braking technology: In 1924, they were the first automotive manufacturer to outfit their vehicles with hydraulic four-wheel brakes. Automotive historians will tell you that was a major advance over the antiquated mechanical braking systems of the day.
In the early 1930s, Chrysler combined forces with Auto Specialties Manufacturing Company (Ausco) of St. Joseph, MI. Within months, the two companies working together developed a series of new brake designs. One was especially significant. It used a stationary disc enclosed by a cast-iron housing that rotated with the spinning wheel. This was basically an early “disc brake” system.
How it worked
The way this new system worked was this: Inside the brake’s cast iron housing, a stationary disc was fitted with six friction pads. This disc itself was split down the middle so each facing section could move outward. The expansion was triggered by dual hydraulic cylinders acting upon small lever arms. The end result was that when these brakes were actuated, less pedal effort was required. Specifically, conventional drum brakes required some 120 pounds of pedal pressure to lock up all four tires in a panic stop but the Ausco-Chrysler disc brakes took only 75 pounds. This was a considerable reduction in force and soon these brakes were outfitted on the two limousines being built for the Eisenhower administration.
They soon were available on standard cars
The Ausco-Chrysler brakes performed so well on the Eisenhower limousines that they soon were being installed on other high-end Chrysler cars. Unfortunately, the Ausco-Chrysler brake systems weren’t cheap to build so Chrysler was forced to make them an expensive option. Records show that about two thousand 1949–1954 Chryslers ended up equipped with Ausco-Chrysler four-wheel disc brakes system. While this number may be small, it created a ground swell of support among automotive designers. Within a few years, disc-type brakes were being used on cars all over the world.
Today
Today drum brakes are all but extinct. Disc brakes won out years ago and are being installed on just about every motorized vehicle made in the World. Is it the final word in brake systems? Can manufacturers relax and call this technology “fully baked.” Probably not. Engineers are constantly innovating so other designs will undoubted be developed in the future but it is unlikely that this will happen anytime soon.