Gauteng Smallholder Dec 2016 / Jan 2017 | Page 47

From page 44 At the same time as cleaning your air filter it makes sense to perform an engine oil change, particularly on a diesel tractor. Like that in a diesel car or bakkie, your tractor's engine oil develops into a dark, black sludge over time as it picks up sulphur and other deposits during the combustion process. As it does so it loses its lubricating qualities and if left in too long will allow excessive engine wear. Think about it: the engine oil in most diesel bakkies is changed at relatively short intervals of often no more than 5 000 km. While one doesn't measure tractor usage in terms of kilometres travelled, is there therefore any good reason why you should not change your engine oil at least once, or even twice, a season? If your tractor has a replace- MAINTENANCE able oil filter it makes no sense to replace the oil without changing the filter. And, while you're about it, if your tractor has a replaceable fuel filter, now's a good time to do that, too. The saying “oil and water don't mix” is not strictly true, as oil (like petrol) is mildly hydroscopic, in other words it absorbs water over time. If your tractor has been standing a long time you probably won't notice this when you check your gearbox or hydraulic oil levels, so it is advisable to start the tractor and work it for a little while before checking the condition of your oil. If it is the colour of horse urine, ie clear yellow or light brown, it is still usable. However, if, after having worked the tractor to mix up the oil thoroughly it appears a little cloudy or milky, replace it immediately as it has absorbed moisture and will cause damage to your machine. Up front, of course, a check of the condition of your radiator fluid is also important. If it is muddy brown with rust, drain the radiator, flush the cooling system and replace the coolant with water and a good dose of anti-freeze. With the liquids in your tractor checked and the filters replaced, the final check before you head off to work is of you tyre pressures. This is most important because the 45 www.sasmallholder.co.za entire torque (power) of the engine is transferred to the ground through the side walls of the driving tyres (both front and back if yours is a 4 x 4 and solely through the rear tyres if a two-wheel-drive affair. With inadequate inflation the rotary force thus exerted causes the tyre walls to flex and fold which will in time cause them to fail, either through cracking of the rubber of the wall or through tearing of the canvas lining inside. QUIRKY