Coolant Hose Clamp
A metal clip or screw clamp used to secure coolant hoses to fittings, preventing leaks under system pressure.
A coolant hose clamp is a metal fastening ring used to secure flexible rubber coolant hoses to rigid fittings on the radiator, water pump, thermostat housing, and engine block. It ensures a leak-free seal capable of withstanding the heat and pressure (typically 12 to 16 psi) of a hot cooling system.
There are two primary types of clamps: spring clamps (constant-tension clamps) and worm-gear clamps (screw clamps). Spring clamps are made of spring steel and apply constant pressure as the hose expands and contracts with temperature changes. Worm-gear clamps use a screw mechanism to tighten a slotted band. While easy to install, worm-gear clamps do not adjust for rubber shrinkage and can damage the hose if over-tightened.
If a clamp becomes rusty, loose, or is installed incorrectly, it can allow coolant to leak or cause the hose to blow off under pressure, leading to rapid coolant loss and engine overheating. When replacing coolant hoses, it is standard practice to inspect the clamps and replace them if they are corroded or have lost their spring tension.