RUNNNG-IN is the most important item in the care of a new car. The running-in mileage is anything up to about 5,000, and never less than 1,000. For at least the first 500 miles the speed of the average car running on top gear should not exceed 25 miles per hour, correspondingly lower limits obtaining on the lower gear ratios. After the first 500 miles the oil should be drained from the engine sump and if a filter is included in the lubrication system it should be cleaned. When the sump has been filled to the correct level with new oil, the next 500 miles can be allowed a higher maximum speed, say 30 miles per hour, on top gear.

All these instructions are usually in the makers handbook and it cannot be too strongly emphasized that the initial running-in period is the most important in the life of the car, and that money is well spent on extra oil and attention during this period.

The gear-box and the back axle must be treated with exactly the same care as the engine, the back axle being very often left too much to take care of itself. Changing the oil frequently in these components during the first 5,000 miles will be well repaid in smoothness and silence of running later on.

After the first 500 miles, when oil should be changed all round, see that the oil is changed every 1,000 miles, or whatever mileage the maker recommends. The reason why it is necessary to so frequently change the oil in a new car is because small particles of metal, usually very minute specks, are loosened in the process of machining the parts during manufacture and do not become dislodged until the parts are actually fulfilling their functions. Whilst on this most important subject of lubrication it is as well to note that the choice of oils is almost always decided by the manufacturer of the car. He should know best. The Engine

IT AVE the ongine decarbonized after the first 2,000 miles. The valves should be ground in and adjusted, and a new cylinder head gasket fitted. After decarbonizing, the engine will not be itself again for some 200 miles, and should still be treated with great respect.

After regrinding, the valves will bed themselves in, and after 200 miles the tappet clearances p.hould be looked to. They are almost certain to ncod adjustment. This is most essential, since the valves will burn away extremely rapidly if the clearances have become too small. Sparking Plugs

PHE sparking plugs should be removed frequently. They can then be taken to pieces with the aid of a couple of spanners, well washed in petrol, allowed to dry, thoroughly brushed with a stiff brush, and reassembled. The spark gaps may need adjustment. A visiting card makes quite a good gauge for the gaps, which should be from 20-thousandths of an inch for magneto ignition to 30-thou-sandths for a coil system. Actually the gaps should be the same as in the contact breaker, and since a gauge is usually provided for these latter, it may also be used for the plugs.

Should traces of rust be found on the parts of the plug exposed to the combustion space, it means that water ha3 leaked . . , , the cylindors and been thrown up on to the plugs. Therefore try tightening down the nuts securing the cylinder head. If this fails to remedy the trouble, then a faulty gasket is indicated and should receive attention. Water Pump I HE water pump may be placed in such A a position that any water leaking out through the gland, i.e.. where the shaft enters the pump casing, will be thrown off the shaft on to surrounding metal work.

As soon as any sign of this having occurred appears, tighten the pump gland. Incidentally the gland must not be tightened too much as this results in loss of power, and may even damago the pump. If any rusty deposit from the water is found it should be wiped off with a rag soaked in paraffin oil, and not allowed to accumulate. Carburettor

PERIODICALLY take off the top cover of the float chamber, remove the float, and clean out any sediment in the float chamber. This usually consists of a very finely-divided whitish powder. Occasionally remove the jets and see that they are quite clear. Take great care in handling the float and its mechanism. A leaky float is rare, but will cause flooding. The presence of petrol in the float may be detected by shaking the float and listening. If a leak is suspected, place the float in hot water for a few seconds and see if any bubbles of air are expelled. If they are not, do not leave the float in hot water as it may become distorted owing to the expansion of the air inside it.

If an air filter is fitted, clean it about everv 2,000 miles, and do not wait till the warning whistle (if one is fitted) blows.

The feed pipes from the tank to the car-burettor must be kept clean, inside and out, as must any filters which may be included in the arrangement. Dirt on the inside of the pipe or in the filters will tend to starve the carburettor at high engine speeds. Dirt on the outside of the pipe very often becomes soaked in petrol and is responsible for a disagreeable smell.

Adjustment of the carburettor is bes1; done by an expert, but il it is attempted, a piece of white paper held at the end of the exhaust pipe will help as a guide. If the exhaust is a smoky black, it means that the vapour entering the engine is too rich in petrol. The colour of the exhaust due to over-rich mixture is quite distinct from that which is due to the combustion of lubricating oil, which is blue.

Water in the petrol separates out and sinks to the bottom. It can be removed by means of a glass tube. Hold the finger over the top of the tube and dip the other end of the tube into the water. Remove the finger, and petrol and water will rise up the tube. Now, before the water has time to sink again, replace the finger and withdraw the tube. If this method cannot be used, then the petrol is best siphoned out of the tank by means of a length of rubber tubing. The water may then be dealt with in any convenient way. Brakes DRAKES should not be allowed to get – too slack but should be adjusted, generally speaking, so that the braking effort on all four wheels is the same. It is a fact that the front wheels will take more braking effort before locking than the back, but it is unwise to try to take advantage of this. Periodically the brake-drums should be removed and the shoes examined. They may need relining. Suspension A BOUT once a year the gaiters should be removed from the springs and the springs greased with a suitable medium.

The oil level in hydraulic shock absorbers should be checked and if necessary re-plenished. Spring shackles are usually fitted with silent bloc bushes and rcquire no lubrication, but if ordinary bushes are fitted, see that they are greased regularly, as otherwise they will squeak and also reduce the efficiency of the spring.

Regularly go round all the grease-nipples on the steering gear with the grease gun, and for safetys sake see that all is in order. The box in which the gear works must be kept full of oil like any other gear-box.

Similar Posts