How To Replace an Upper Radiator Hose?

Are you getting worried about the green liquid dripping beneath your car? Do you notice that you’ve been refilling the radiator more frequently to keep your engine cool? If yes, you must have a problem with your radiator hose.

Radiator hoses are responsible for giving coolants a smooth flow from the engine to the radiator and vice versa. The upper radiator hose connects the thermostat to the radiator.

With this hose working properly, the engine maintains its working temperature preventing further damage. You will need working radiator hoses to keep the cycle running.

When is it time to replace the upper hose?

  • When it’s leaking
  • When there’s a low coolant level
  • When it collapsed
  • When it cracked
  • When it broke

Finding protruding, torn, swollen, or cracked parts signifies that you need to replace your upper radiator hose. It results in leakage or irregular cycling.  The last thing you want to see is an overheating engine, which leads to engine failure.

So how do you replace the upper radiator hose?

How to Replace the Upper Radiator Hose?

Things you’ll need:

  • Pliers
  • A new set of hose clamps
  • A new hose (ensure that it’s compatible or the same as the old one)
  • Screwdriver
  • Jack
  • Jack stand
  • A catch or dripping pan
  • Container
  • Nitrile gloves
  • Safety goggles
  • 50/50 premixed coolant
  • Air compressor (optional)
  • Vacuum fill kit (optional)

Before you start replacing the upper radiator hose, make sure to turn off your engine and let it cool. Remember that hot coolants can injure anyone exposed to it.

Once the tools are ready, prepare your workspace. Wear your gloves and safety goggles. Organize the tools you need and place them within a convenient reach.

A Step by Step Guide to Replacing an Upper Radiator Hose

  1. When the engine has cooled down, start lifting your car with a jack and jack stand. Block the rear wheels and set your parking brake.
  2. Locate your upper radiator hose. It’s thicker than the lower radiator hose. You can see it connecting the thermostat housing and the radiator.
  3. Put in the catch pan below the radiator hose.
  4. Drain the old coolant. Open the petcock to drain the coolant or remove the lower hose. Make sure it is cool to avoid injuries.
  5. Remove the radiator cap.
  6. Loosen the clamps at both ends of the upper radiator hose.
  7. Gently slide off the hose from both ends by twisting it from the left and right.
  8. Remove excess coolants in the hose. Pour it into the drip pan.
  9. Slide in the hose clamps to the middle of the hose.
  10. Slide the new hose on the connectors of the radiator and engine. Push it as far as you can.
  11. When the hose is firmly attached, tighten up the clamps at least 1/4 inches from the hose ends. Make sure the clamp holds firm on the raised part of the connector.
  12. Close the petcock.
  13. Lower your car and remove the jack stand carefully.
  14. Fill the radiator with the premixed coolant. Make sure that you are putting in the right mixture. Take note that some methods may require continuous filling during the bleeding process.
  15. Bleed your car’s cooling system. Attach the vacuum cooling system if there is. Or, start the engine, wait for the engine to reach its operating temperature until it creates bubbles out of the radiator.
  16. Top off the coolant.
  17. Close the radiator cap.
  18. Test the cooling system. Start the engine. Monitor the cooling gauge and check for leaks.

If you suspect coolant leak, here’s how to diagnose and fix it.

Bonus tips!

Most of the time, the upper hose won’t slide off easily. Use a carpet knife or a flat screwdriver if you need to lift the hose tips.

Another way to bleed the system is to see if your vehicle has a bleeding valve to purge the air out.


Make sure to turn the engine off before getting your hands on the radiator and engine. Use nitrile gloves as these can protect you from harmful chemicals.

Do not forget to lower down your vehicle before bleeding. Use a jack stand when lifting the car. Use safety shoes to protect your feet.

The Final Verdict

Now that you know how to replace your old upper radiator hose, you should also change your lower radiator hose. These hoses work up to five years before they get worn out.

By replacing the hoses, you can prevent the engine from overheating that can lead to engine failure. Of course, you want to avoid more repair costs, right?

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