This tank holds extra coolant for your engine. Coolant, as you probably know, circulates to keep things from overheating. As the engine heats up, the coolant expands. Instead of just overflowing somewhere, the excess liquid goes into this tank. When the engine cools down, it creates a vacuum and the tank allows coolant to be drawn back into the system to maintain the right level. It's a pretty simple idea, really. It’s part of the cooling system, obviously, and it sits right in line with the radiator and engine. It’s not directly making the engine run, but it's vital for keeping everything at a safe temperature. Think of it like a pressure relief valve. Without it, the pressure could build up and damage hoses or even the radiator itself. Because overheating is a serious issue. If your engine runs too hot, it can warp the head, blow a head gasket, or even cause catastrophic damage. The expansion tank helps prevent that. It keeps the system sealed and maintains the proper coolant level, acts like a shield against pressure build – up, and helps prevent air from getting into the system. You’ll notice if it’s failing—you might see coolant overflowing, a loss of coolant without obvious leaks, or maybe even temperature gauge fluctuations. You can find a replacement for a pretty good price over at Fixparts Online, if you decide it’s time for a new one. Keeping the cooling system healthy really extends the life of your engine. Highly recommended: Lock (MPN 17137516004) comes with a 12-month warranty!

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