Watch for signs of failure with your Isuzu water pump after the first 100,000 miles on your vehicle. If you diagnose your water pump's failure before a major engine overheating episode occurs, you can prevent major engine damage - and the exorbitant repair bills that follow. Save yourself some major engine repair bills by ensuring you have enough coolant and water in your system. Check your hoses regularly for leaks. Change your coolant every two to three years, since the coolant losses its anticorrosive powers over time. Most standard antifreeze mixtures will do that in about 2 years or 24,000 to 30,000 miles. Every five years, get your Isuzu coolant system flushed. That will help clean out the corrosive filth that has collected in your cooling system over the years. In addition, the air, gasses, impurities, deposits or rust in the coolant fluid will be removed by the flushing. Use distilled water, which reduces the levels of calcium, lime and other minerals that will clog your radiator. If it's an emergency and there is nothing else available, use tapwater but be aware that softened water contains salts that will damage the cooling system. Manually check the Isuzu water pump pulley to see if the bearings are giving way. By taking a few extra maintenance steps, you will lengthen the lifespan of your Isuzu water pump, and keep your engine running smoothly.