How to Replace a Leaking Radiator Hose

Replacing a leaking radiator hose can be easy and quite painless on most cars. Check that both ends of the leaking hose are easily accessed before attempting this repair, because on some cars the hoses are tightly tucked away and this job might be better left to a professional.

Difficulty: Challenging

Instructions

Things You'll Need:

• WD-40 Silicone Spray
• Large Pan Or Wide Bucket
• New Radiator Hose
• Antifreeze
• Utility Knife
• Funnel
• Flathead Screwdriver

1. Turn off the engine as soon as you suspect a leak, to prevent the engine from overheating.

2. Determine which radiator hose is leaking and exactly where the leak is coming from by looking for wetness.

3. Purchase 1 gallon of antifreeze and the correct replacement radiator hose from your local auto-parts store or dealer. (Radiator hoses are not interchangeable. They come in specific sizes and shapes for your particular car model.)

4. Wait for the engine to cool down for at least 20 minutes, before beginning any work on the cooling system.

5. Place a large pan or wide bucket on the ground under the hose to catch the coolant.

6. Use a screwdriver to loosen the hose clamps at both ends of the hose you are replacing.

7. Remove the radiator hose by twisting and pulling where it connects to the radiator and engine. If the hose won't budge, use a utility knife to cut it off the fittings.

8. Remove the hose clamps from the old radiator hose and slide them onto the new hose.

9. Put the new radiator hose on. Spray the inside of the hose ends with WD-40 if the hose is hard to get on. Tighten the hose clamps.

10. Refill the radiator and the coolant reservoir with a 50-50 mixture of water and antifreeze.

11. "Burp the cooling system" by running the engine with the radiator cap off until the engine warms up. Keep the engine running until both the upper and lower radiator hoses feel warm (this indicates that the thermostat is open and the coolant is flowing through the entire system). Burping the cooling system allows any air bubbles to escape. Add coolant to the radiator as needed.

12. Look for leaks. Inspect around the hose clamps for dampness. Tighten the hose clamps if there is any wetness.

13. Put the radiator cap back on.

14. Check the coolant level after driving, to ensure there are no leaks.

Tips & Warnings

• If the leak is coming from around the clamp holding on the hose end, tighten the clamp with a screwdriver. This may be all you need to do if a loose clamp is causing the leak.
• In a pinch, you can add either plain water or pure antifreeze if that's all you have, but your cooling system normally uses a mixture of 1/2 antifreeze and 1/2 water.
• Never open the radiator cap or loosen a radiator hose clamp when the engine is warm or hot. The coolant could spray out and burn you.
• Dispose of used coolant properly. Bring it to a repair shop or parts store for recycling. Do not pour it down the sink or into the gutter.

Who Can Help Sponsored

[esonstar]

on 6/17/2009 Wow, thank you SO much for the how to. I have never had to replace a hose on my car before, but your how-to walked me through every step clearly. Being a woman, I was somewhat unsure and this was just what I needed.

[shimmybug]

on 4/16/2009 Thanks so much for your how-to article. Changed the radiator hose of my first car (1973 AMC Gremlin) about 10 years ago--but was a little bit worried about changing my newer Accord's! You saved my femmey gaymo ass today--thanks!

on 11/22/2005 When you are fitting the new hose in place, if you have a set of screwdrivers handy, use the largest screwdriver in the set that will still fit the hose clamp slot so as to gain the maximum tension and therefore a more effective seal.

on 11/22/2005 A good way to tell if there's pressure in the cooling system is to squeeze the upper radiator hose. The harder the hose, the more pressure you have in the cooling system.