THE BRAKES

Rotorua Morning Post, Volume 3, Issue 682, 7 November 1933, Page 2

THE BRAKES

Rfe'GULAR INSPECTION NEEDED TO COMPLY WITH LAW. The law requires that motor cars shall be fitted with two- entirely independent braking systems or with one system having two independent means of operation, so arranged that the failure of any part will not prevent the brakes on two wheels effectually stopping the vehicle within a-reasoh-able disthnce, sa-ys the Light Car and Cycle-car. There is a further f'equirement that the brakes shall always be maintained in an efficient coriditibii. There ar'e three types of braking systems in common use on light cars; the direct mechanical, th'e self-servo and the hydraulic. They vary considerably in 'details of design, but to all of them certain of the usual mainteri^ ance and adjustment methods are applicablo. It is very important that th'e brakes on all four wheels should work With equal efficiency, as otherwise not only is the stopping distanee increased, but 'there is also a considerahle risk of skidding. Great accufacy of setting can he obtained by having the braking power measured on one of the special testing machines, such as may he found in most large service stations. These machines give the retarding effort 0n e'ach wheel in figures so that precise adjustment can be made and the driver may then take the- road with th'e assurance that his brakes are as hiighly efficient as it is possible to make them. The means for making in'dividual adjustments of mechanically operated (brakes are generally of a very straightforward kind, such us wing nuts on the ends of the brake rods where they pass through trunnions on the cam spindle levers. Com.mion Braking Troubles. Naturally, no amount of careful adjustment of Lockheed, Bendix, or any other type of brake can he effective Jf the friction linings are oily ior otherwise faulty. lOil on the linings is, however, a fairly comimon occurrence — at least on old cars — iand one which is not easily put right, except by renewing the linings. It is true that the oil can sometimes be cleaned off with petrol or with carbon tetrachloride, i.e., the liquid used in certain types of fire extinguishers. Similarly, it may be possible to burn off the oil by heating th'e linings with a blowlamp, but this cannot be recommended because it may be bad for the shoes themselves which nowadays are nearly always made of aluminiuin, and, in the second place, because ibrake lining material — although it generally has an asbestos base and is practically fireproof — can be harmed considerably hy being overheated. iScored brake drums are another cause of lost efficiency, and the only cure is to have them machined smooth, in which case, of oourse, thicker linings will probably be necessary to make up the difference in the diameter. Very thick linings are not always advisable, so by far the best plan, if it is necessary to machine the drums, is to have h'ardened steel liners fitted.

This scheme is meeting with considerahle favour, as it ensures a maximum of brakintg, efficiency for the minimumj need for adjustment, ias the hardened drum liners bring about a very consideraible reduction in the wear of the friction linings themselves. Furthermore, the brake drum diameter remains standard so that no difficulty will be 'experienced in obtaining the correct thickness of friction material should renewal eventually become necessary.