All The Car Owner Needs To Know About Anti-Freeze

Waimarino Bulletin, Volume 4, Issue 48, 19 May 1987, Page 6 (Supplement)

All The Car Owner Needs To Know About Anti-Freeze

NOT so long ago, canny car-owners observed the ritual of flushing and refilling their radiators twice a year - usually in autumn and spring. Those were the days when it was generally accepted that although anti-freeze was effective in preventinga cracked engine block or a burst radiator in the depths of winter, it did not do anything for the cooling system if left in for prolonged periods. Since then attitudes towards anti-freezes have changed. The modern antifreeze not only prevents iceup in winter, but also coolant loss, because of boiling, in summer. Water is not the most efficient engine coolant because it freezes at Odeg C. a relatively high temperature, and boils at lOOdeg C, a relatively low temperature. Moreover, water corrodes the metals employed in a car's cooling system. I he canny car-owner was probably wise to observe those autumn and spring rituals, but nowadays an ethylene glycol-based antifreeze/ coolant has been developed to satisfy the needs of modern engines. I he formulations contain corrosion inhibitors added in sufficient concentration to afford metal protection. Corrosion inhibition is one of the reasons why a reasonable concentration of anti-freeze/ coolant should be retained in the engine cooling system the year round. That concentration can vary between 20 and 50 per cent. However, it should be borne in mind that the concentration of anti-freeze/ coolant will drop with toppingsup of the radiator over an extended period, so the inhibitor becomes depleted. Under the circumstances, it makes sense to flush out the cooling system annually, the most appropriate time to do it being autumn, just before the onset of winter. Provided one reads and understands the instruclions regarding concenlrations that will come with the antifreeze/ coolant, there is no reason why the task of flushing out the radiator and refilling it should not be done by a car-owner. On its own, the procedure is quite straightlorward. However, there can be more to it than at first meets the

eye. I'here is mere to flushing a cooling system than just removing the cap from the radiator header tank and simply poking a hosepipe into the tanks and turning on the tap full bore. That is only half the job. To rid the radiator of scale and debris, the radiator should be bottomflushed also. Bottom flushing involves removal of the radiator bottom hose and forcirig water from a hose pipe up through the radiator. It is not really an earlymorning job on a cold Saturday or Sunday in autumn, especially if, on removal, the bottom radiator is found to be perished. In that case, the handyman must set off for the nearest service station to secure a replacement hose. Whai might have been a 90-minute job finally strelches into the afternoon when

the dew has started to fall and made the lawns too wet for their last mowing before winter. On the other hand, that bottom hose could have been as good as gold and the complete job accomplished without trauma. But, take heed, when the cooling system has been refilled with the water/ antifreeze/ coolant mixture. Antifreeze/ coolants are notorious for revealing leaks, especially after all the scale and debris that has accumulated in the course of a year has been cleared out. Bearing in mind that the efficiency of the cooling system is conducive to ihe most efficient operation of a car, as well as the most costeffective running, it makes sense to have an expert check the system at least annually.