A radiator hose carries antifreeze coolant to and from the radiator on your engine. On most vehicles, there are two main radiator hoses. The upper radiator hose carries coolant from the top of the radiator to the top of the engine to keep it from overheating. The lower radiator hose connects the bottom of the radiator to the water pump, which pumps the coolant throughout the system. Both hoses are connected to their ports with hose clamps. If either one of these hoses develops a leak, or if one of the clamps fails, your antifreeze will leak out and your engine will overheat.

How to maintain your radiator hoses

The good news is that radiator hoses last for about 10 years or 100,000 miles. New cars should have their hoses inspected about every 20,000-30,000 miles. On cars more than 10 years old or with over 100,000 miles, you should have your hoses inspected every 6,000-10,000 miles, or with every other oil change. You can inspect your own radiator hoses if you know what to look for. After locating the hoses, you can:

1. Visually inspect them for cracks, fraying, or bulges.

Cracks and fraying can happen when the rubber in a hose dries out over time, and bulges develop when the rubber begins to weaken over time. If you see any of these things, replace the hose as soon as possible.

2. Squeeze each hose.

A radiator hose should be firm, but not overly hard or too soft. If you’re not sure how it should feel, you can visit our product page on how we handle some of the new hoses we have. This will give you an idea of how a healthy hose should feel. You may find that most of your hose feels firm, but that there is one particular spot that is soft or overly hard. A hose in this condition needs to be replaced.

3. Check the clamps that attach the hose to either the engine or the radiator to make sure that they are snug.

They may have to be tightened on occasion. If you can turn the clamp by hand at all on the hose, it’s too loose. For ring or band clamps, you will need a screwdriver. You will need pliers to adjust wire clamps.

Radiator hoses can be difficult to locate and reach to inspect. It may be necessary to go under the car to access and replace the lower radiator hose. We recommend visiting a professional mechanic to inspect them in a Service Center with a lift.

For more tips on auto repair and vehicle maintenance, visit our Automotive blog.