FOUR-WHEEL BRAKES

Dominion, Volume 22, Issue 133, 1 March 1929, Page 8

FOUR-WHEEL BRAKES

CORRECT ADJUSTMENT NECESSARY Considerable advancement has been made in the past few years in brake types and designs, but unless brakes are correctly adjusted and cared for the owner of the car will not receive the advantages of the improvements (states the Service Manager of General Motors, New Zealand, Limited). Owners of cars have been heard to remark that the two-wheel brakes of their previous ears were as good as the four-wheel brakes of their present cars. The reason for this is that the adjustment of the four-wheel brakes has been wrong to a point where it was only a two-wheel-brake car, as far as braking power was concerned. With Improvements in engine design, acceleration has been increased to such a point that car manufacturers have found it necessary to deal seriously with deceleration. By providing brakes on all four wheels they have succeeded in coping with th'« problem. However, regardless of the type of brake, the owner by careful operation and attention can prolong the effective life of the brakes of his car. Complaints such as hard pedal travel and grabbing brakes can be obviated in many cases by attention to the lubrication of the brake mechanism, especially shafts and pins which are exposed. A dragging brake is usually due to one of the following causes: lack of sufficient clearance between the brake drum and lining, a high spot in the brake band or a brake drum running out of true more than the clearance provided by the design of the brakes. Rapid loss of adjustment may be due to loose lock nuts, poorly rounded brake bands, a loose back anchor connection, or brake lining loose In the bands.

A good average formula to work on when adjusting four-wheel brakes is 40 per cent, pressure on front drums and 60 per cent, on the rear. Squeaking and fouled brakes are the commonest of brake complaints. Squeaking is attributable to one or other of two reasons: spot contact or abrasion. Misaligned bands or shoes or rivets bearing against the drum will cause squeaking through sp’t contact. Abrasion is the result of foreign matter and road dirt collecting on the surface of the lining. It is sometimes caused through rivets of improper metal having been used when the brakes were re-lined. In some cases, dirt can be removed by applying the brakes for a short period. If the complaint cannot be remedied by this method it is advisable to remove the wheels and wash the linings, with gasolene or buff the dirt off. A good driver when driving over wet clay or dirty roads applies his brakes occasionally so as to keep the surfaces of the linings as clean as possible.