What size hose goes on the heater core?

There's no single answer to what size hose goes on a heater core. The hose size varies drastically depending on the make, model, and year of the vehicle. The hoses are also often different sizes on either end of the heater core itself.

To find the correct hose size, you must consult:

* Your vehicle's repair manual: This is the most reliable source.

* A parts store using your vehicle's year, make, and model: They can look up the correct parts, including hose sizes.

* The old hoses: Measure the inside diameter (ID) and outside diameter (OD) of your existing hoses before replacing them. However, remember that hoses can degrade over time, and the original size might not be the optimal size for a replacement.

Trying to guess the hose size can lead to leaks or poor heater performance. Always use the correct size hose to ensure a proper fit and prevent problems.