7.21601 DT Expansion tank

This thing holds extra coolant for your engine. Coolant, as you probably know, circulates through the engine to keep it from overheating. As the engine heats up, that coolant expands—that’s just physics. The expansion tank gives that expanded coolant somewhere to go, prevents pressure building up in the system. It also provides coolant back into the radiator as the engine cools down and the fluid contracts. Essentially it manages the volume changes in your cooling system. It’s part of the cooling system, specifically connected to the radiator usually through a hose. It's a sealed unit, meaning it holds pressure. It doesn’t make the coolant circulate—the water pump does that—but it's a critical piece in maintaining the proper coolant level and pressure. Think of it as a safety valve and a reservoir all in one. It works with the radiator cap to keep everything at the right pressure. If the expansion tank fails, you can run into a lot of trouble. A cracked or leaking tank means you're losing coolant, and that leads to overheating, which can cause serious engine damage. You’ll notice if it's failing—you might see coolant leaking, or the engine temperature gauge creeping up. It acts like a shield against pressure build – up, so if that shield goes, things get risky fast. Ignoring it can lead to a blown head gasket or worse. You can find a replacement pretty easily, places like Fixparts Online usually have a good selection, and it’s often something a reasonably handy person can replace themselves. All-season performance: Expansion Tank (MPN 7.21601) comes with a 12-month warranty!

About DT

DT is a reputable German brand specializing in high-quality spare parts for commercial vehicles. Based in Germany, DT provides reliable components that support the durability and performance of automotive fleets.

Why Choose DT?

• We have a huge selection of parts, so you’re likely to find what you need, fast. • Our prices are competitive, meaning you get great value for your money. • We focus on quality parts that are built to last, saving you time and hassle. • Our customer service team is here to help – we'll get you the right parts and answer your questions. Drive with confidence – choose DT parts at FixParts Online.