HINTS FOR MOTORISTS.

New Zealand Herald, Volume LXIV, Issue 19608, 9 April 1927, Page 10 (Supplement)

HINTS FOR MOTORISTS.

(11). BRAKE ADJUSTMENTS. . In the hilly city of Auckland brakes arc no doubt kept at a higher < standard of efficiency than would bo disclosed by a census on the brake mechanism of cars used on the plains of Canterbury. Steep grades compel attention to brakes, or, at least, to foot brakes. It is remarkable how many car owners neglect the hand brake, and - if it were not for the excellent brake afforded by leaving the car in low gear, many a car could not be left standing in some of the steep parking areas within a hundred yards of Queen Street. Not that any objection should be taken to this use of the gear lever. It is a very assuring safeguard, but, unfortunately, scores of drivers allow their handbrakes to drift into inefficiency because of the use to which the gear can be put. A car which was recently parked on a steep outlet to Queen Street, was removed by joyriders. Although the car had been fitted with a gear lock, the owner had left the key behind. He confessed that he had found that his hand brake was not holding too well, and that he had to fall back on the low gear, a recourse which debarred him from locking the lever in the usual position. It is usually possible to detect when the linings of external contracting brakes are worn beyond adjustment, and continued use will only mean that the projecting rivets will afford a. f(sfeble grip. Internal brakes are open to suspicion, when adjustment fails, to improve the grip. Although many external brakes may be repaired without removing the wheels, much trouble is saved if the wheels are removed with wheel puller, and opportunity can be taken to inspect the internal brakes. Few tools are needed for relining. A drill for countersinking in the lining is useful, although not essential. Copper or brass rivets and a punch complete the equipment. Asbestos lining with brass wire intervening, can be bought by the foot. A clamp for holding the lining to the brake band while riveting, greatly facilitates the work. The lining should not be countersunk more than half its depth, and the rivets should be long enough to project about l-Bin. above the lining before clenching. Tubular rivets are usually used for internal brakes with solid shoes, while split rivets are easier to use (heir external bands. If the brakes are not compensated, it is necessary to test the adjustment after repairs by comparing the pressure exerted on each drum. If the braking effect is not distributed, the car will steer to one side, wear tyres unevenly, and overheat the drum, which is doing the largest share of the work. Hand brakes are often damaged by repeated careless application. The ratchet will wear rapidly unless the grip is pressed when pulling back the lever. Grease should be applied to the ratchet occasionally, and tests made to see if the brake rods return under spring tension after release. A slight jamming of the brake will cause a great loss of power. Glazed brake linings will often reduce the grip, and washing with petrol is_ sometimes effective in removing dust. Oil on the brakes is fatal. Following are the performances to be exexpected from efficient brakes. SpeHs in Distaiicfi in which car should Mules he pulled up. per hour. 2-wheel brakes. 4-wheel brakes. 10 - 9.3 ft. 6 ■ ft. IS .. ■■■ 21 ft. 1 3.5 ft. 20 • 37.5 ft. 24 ft. 25 58.1 ft. 37.5 ft. 30 84 ft. 54 ft. 35 114 ft. 73.5 ft. 40 150 ft. 96 ft, 50 232.4 ft. 150 ft. RECORD BREAKING. . The South Island Motor Union has recorded its disapproval of record breaking trials over New Zealand roads. The complaint arose out of a recent run made by an Australian driver for publicity purposes. The Motor Union has suggested that the Government could easily discourage such tests by prohibiting the publication of any details relating to high speed performances. The same attitude is being taken in Great Britain, and a storm of protest has been raised in connection with a circular issued by a motbr firm relating to a drive from London to Edinburgh under nine hours. The speed claimed is 471- m.p.h. for the run of 420 miles. RACING BODIES FOR 1927. This year's international racing rule is a continuation of that of 1926 so far as the engine is concerned, namely, piston displacement of 1500 c.c., with superchargers allowed, but it embodies important body changes. The minimum width is 80 centimetres (312-sin.), and this width must be maintained over a length of 80 centimetres, while the body must have a height of 25 centimetres (9 4-sin.) along the length of 80 centimetres. There are no restrictions as to the number of seats or the position of the driver, and as a consequence cars with the steering at the left or the right, or in the centre, will ,be eligible. This change has been made in order to facilitate the entry of American and European cars in European races, but up to the present no notification has been received that the United States of America will enforce the European width of 80 centimetres. In 1928 the international racing rule will allow full liberty, with the exception of a minimum and a maximum weight. At first it is not likely that there will, be am? important changes, for the fastest cars in existence, over any long distance, are undoubtedly the existing 2000 c.c. models, with the smaller 1500 c.c. types closing up on them very rapidly. Construction has reached such a stage that other factors than piston displacement are not predominant in determining speed.