Putnam's Automobile Handbook: The Care and Management of the Modern Motor-Car

by H. Clifford Brokaw; Charles A. Starr

Look well to the condition of the brakes on your car before starting on a trip. See that they are in good shape even if you do not have time to look over the engine. The brakes are more important than the engine. It needs an engine in at least fair condition to get anywhere, but if you do not have brakes you may get too far—too eternally far.

Manufacturers of cars have recognized the importance of the brake appliances and have given considerable attention to the improvement of the brake, designing more efficient operating mechanism, increasing the size of the braking surface and improving the quality of the friction materials, and also in protecting the brakes from excessive wear due to grit and dragging of bands when not in use.

The brakes, moreover, on the average car of modern design, are sufficient for all general use, if used intelligently and if they are given a moderate amount of care. But like most other parts of cars, some owners give them no attention whatever, and consequently there is frequent failure and often it is a matter of life and death when the brakes refuse to work properly.

First of all, owners should understand that there are two sets of brakes on the car, which operate independently of each other, and each brake should be capable of holding the car at a standstill on practically any grade, or, as the chauffeur usually puts it, “sliding the wheels.”

A recent experience with a Ford car illustrates the need of the owner thoroughly understanding his braking system. This was a case of a new car where the owner had not yet become very familiar with the mechanism. He came to a very long and fairly steep hill. He released the clutch and applied the brake as he had been taught, and got about two-thirds of the way down the hill when the brake lining burned out and the brake no longer held the car. Then, because he forgot what he ought to do (or else did not know), the owner lost his head and thought he was going to smash, and of course did. The car ran into the ditch and upset, bent the front axle, broke the mud guards and top bows, and mixed things up generally, but fortunately no one was hurt.

This was all unnecessary, for on this particular car he had three other means of braking. He could have pushed the pedal which engages the low-speed gear and kept the car at low enough speed to negotiate the hill in safety. Or, he could have pushed the reverse pedal, which on this particular car would have acted as a very efficient brake. And, also, he might have applied the emergency brake, as on any other car.

As every car is equipped with two distinct sets of brakes, drivers should learn to use first one and then the other on long grades, and this may be helped out considerably by using the motor as a brake—that is, by cutting off the ignition and allowing the machine to push the engine under compression, and even more by engaging a lower gear before cutting off the ignition, so that there is a greater leverage obtained to retard the car. Likewise, long grades should be descended at a comparatively slow speed in cases where the brake is at all necessary, because the higher speed develops more heat and the brake lining is more likely to burn out.

Of course the brake lining has been improved so that it does not actually burn out very readily, but under extreme conditions it will become charred and lose its frictional qualities.

Perhaps one of the greatest causes of brake failure is oil. Now the oil which gets on the brakes usually works through the rear-axle housing from the differential gear. The owner may be a little too enthusiastic about lubrication and may put too much oil in the differential and it travels along the inside of the axle tube. The wheels are so placed on the axle that this oil can get out only by working over the wheel bearing and into the brake drum. It will often be noticed that the oil collects mostly on the right-hand brake. This is because the crown of the road, and perhaps the ditch alongside of the road which is used in passing other cars, tilts the car so that the right-hand wheel is lower than that on the left-hand side. Even where too much lubricant is not used, it seems that some cars have a tendency to leak oil from the right-hand wheel housing.

Usually this trouble may be overcome by taking a long, thin strip of hard felt of the proper thickness to fill the space between the axle shaft and the axle housing, and winding around the shaft in helical form, so that the action, when the shaft is turned, is to force the oil back toward the differential. Of course, if the felt is not wound in the right way it would have the opposite tendency and draw the oil out into the wheel bearing.