THE COOLING SYSTEM

Hawera Star, Volume L, 21 February 1931, Page 12

THE COOLING SYSTEM

INS URANGE AGAINST TROUBLE.

' ‘ Motorists who wish to enjoy troublefree driving should have a certain amount of work done periodically on the cooling system of their engines. Like any other part of the automobile it requires regular care, and the small cost of the preventive service needed is cheap insurance against engine trouble and possibly heavy repair bills. The cooling system should be in the best possible condition to avoid overheating in warm weather. The average car owner probably does not realise that the cooling system may be in need of attention until after a hard drive on a hot day or some other condition out of the ordinary brings on overheating. Rust accumulating in the engine block and radiator seriously interferes with cooling, and a loss of power and overheating will sooner or later result if it is not removed.

, There is no way of telling from outside inspection how badly the cooling system is clogged until overheating develops. The average car requires a more thorough servicing job than merely tightening .parts to stop leaks and rinsing the radiator with clean water. Radiators showing signs of leakage should be repaired and hose connections should be renewed at least every 10,000 miles. Worn pump packing and leaking water gaskets should be replaced. The fan belt should be carefully adjusted or replaced if necessary. Slipping of the fan belt is almost certain to cause overheating. It is equally important that the entire cooling system, including both tjhe radiator and the water jacket of the engine be thoroughly cleaned of rust and scale deposits that have accumulated during previous months of driving. It has been definitely .proved that cooling system service must be based on the mileage of the car and not on its age. In other words, a car that travels 5000 miles in six months requires more attention to the cooling system than a car that travels only 5000 miles a year. ed circulation in the cooling system. Amongst these are rust, scale, particles of rubber from worn hoses, impurities in the water used, grease from water pump nipples, etc. Most noticeable of all these destructive agents at work within the cooling system is rust, which is formed by the action of air and water in combination on the iron and steel parts of the cooling system, the greatest exposed areas of which are in the engine block. Rust does not form in the radiator core, but is carried there by the action of the water. The amount of rust formed is largely governed by the quantity of air which is induced as the result of severe operation, fast driving, or improper maintenance. The more air the more rust. Air is present in that portion of the top radiator tank not filled with water, and it is drawn into the cooling system by various means. If the water level is low enough to expose the top of the radiator core, air will be drawn into the water passages by the action of the water pump. As the air is sucked out of the top tank, it is replaced by a. rush of air up the overflow pipe, thus completing the circuit. Air can also be sucked in directly at the -water pump. Quite i often a small water leak at the packing nut, which is noticeable while the car is standing, becomes a. source of aeration while the car is in motion; the suction of the pump being sufficient to draw air through the leak. Thus, no water is lost while the car is in motion, but air is mixed with the

water stream, causing greater ru formation.

Many radiators have been found to be clogged with grease and .rust —the grease coming from the water pump on which the ordinary chassis lubricant has been used. If a good reliable waterproof grease is used to lubricate the pump no trouble will result, but ordinary lubricating grease will soften with hot water and run into the cooling system, where it contributes to clogging of the radiator. A good practical way to clean a cooling system is to drain the system by disconnecting the lower hose. This will evacuate the system quickly and the rush of water will carry away some of the accumulated rust. Next connect the lower hose and close the dirainooeks, pour iabout a gallon of kerosene into the empty system and almost fill with water ; then start the engine and allow this mixture to circu- J late for 15 or 20 minutes. Open all draincocks and the lower hose and allow the oil, water and sediment to gush out. Reassemble the lower hose connection and pour in a solution of washing soda (£lb of soda to each gallon of water) and fill to about four inches below the top of the radiator. Start the motor and, with spark retarded, run at a medium speed until hot. Run hot for 10 or 15 minutes. Stop the engine, disconnect the lower hose and drain the entire system. A surprisingly large quantity of rust-, scale and sediment will be drained out.