How to Replace a Radiator Hose

The radiator hose is an important part of your vehicle’s cooling system. The hose carries the coolant to the radiator, where the fluid is cooled, then back to the engine to keep the vehicle from overheating. This allows your vehicle to operate at the perfect temperature and provides you with a smooth ride.

There are two hoses that connect to the radiator. The upper hose attaches from the top of the radiator to the top of the engine. The lower hose attaches to the bottom of the radiator to the water pump of the engine.

If the radiator hose of your car fails, it can lead to loss of coolant and subsequent engine overheating. Overheating can lead to further engine damage. If you suspect that either radiator hose is failing, replace the faulty hose as soon as possible.

Part 1 of 2: Remove the leaking radiator hose

Materials Needed

removing radiator cap

Step 1: Remove the radiator cap. Wait until the radiator cap is cool to the touch. Then remove it and set it aside.

  • Warning: Do not remove the radiator cap when it is hot! The system is under pressure and the cap may burst off, burning you with hot coolant.

draining coolant

Step 2: Drain the coolant. Place a clean container below the vehicle, right under the radiator.

radiator petcock

Drain the coolant either by opening the drain petcock or by sliding back the clamp on the lower radiator hose (see the following step for the hose removal procedure).

loosening hose clamps with a pair of pliers

Step 3: Loosen the hose clamps. Loosen the clamps at each end of the hose. The hose clamps are typically either of the spring tension or screw tension design.

To remove a spring tension clamp, squeeze it with pliers and pull it back on the hose, away from the connection. To remove a screw tension clamp, simply loosen the clamp with a screwdriver, then pull it back on the hose, away from the connection.

removing a radiator hose

Step 4: Remove the radiator hose. Once you have the clamp off, you can remove the radiator hose by twisting and pulling it off the fitting.

  • Tip: If the hose is stuck on the connection, slit it with a razor blade. Do not cut so deep that you damage the connection. After being cut, the hose can be peeled back and discarded.

Part 2 of 2: Install the hose

Step 1: Slide clamps over the replacement hose. Slide the hose clamps over the replacement radiator hose but do not tighten them down.

installing the radiator hose remove text

Step 2: Install the radiator hose. Slide the hose onto the connector.

Then, position and secure the clamps at least 1/4 in. (6.35mm) from the ends of the hose. Check to ensure the clamps are located beyond the raised bead of the connector and then tighten them down.

filling radiator

Step 3: Refill the radiator. Close the drain petcock or reinstall the lower radiator hose. Then fill the cooling system with a 50/50 mixture of coolant and distilled water.

  • Tip: The easiest way to ensure you are getting the proper radiator fluid mixture is to buy pre-mixed radiator fluid.

  • Note: Some methods for bleeding the cooling system require filling the system during the bleeding process.

bleeding air from the system

Step 4: Bleed the cooling system. Whenever you service the cooling system, you must bleed it to remove air, otherwise overheating may result.

There are a few different methods for bleeding the cooling system:

different ways to bleed the cooling system

Step 5: Top off the coolant. Top off the coolant in the radiator and reservoir. Then, reinstall the radiator cap. Run the engine and check for leaks.

It is a good idea to replace the hoses every 5 years or for every 40,000 miles. If you see coolant (red, yellow or green fluid) on your driveway, get the car inspected for leaks immediately. Driving with leaking radiator hoses can cause severe damage to the engine.

It is important to replace worn or leaking hoses to prevent future failure of these hoses where they may burst, causing engine overheating. Since replacing a radiator hose on your own can be messy, you may want to request a professional mechanic, such as one from YourMechanic, to do it for you.


The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does a Radiator Hose Last?
Your Your car’s engine needs coolant in order to operate safely. Automobile engines generate a significant amount of heat while operating, and that heat must be removed and limited to a specific temperature range. If allowed to overheat, the engine...
How to Replace a Coolant Tube
The bypass hose in the coolant system may have failed when the coolant level is low and there is a visible leak underneath the vehicle.
How to Find the Source of a Coolant Leak Faster and More Accurately
Keeping a good coolant level in your car is necessary to avoid overheating. If you think there is a leak, find where it's coming from to fix it.

Related questions

Coolant keeps leaking
Hello. The motor that is in your car (https://www.yourmechanic.com/cars/pontiac/grand-am) is known to leak antifreeze from its lower intake gasket. You will usually never see any antifreeze on the ground when/if this happens. Replacing the lower intake gasket should solve this...
External leak and car losing coolant
Hello! If there was a loud ticking noise you may have some internal engine damage. But I wouldn't go replacing the lifters just yet. I would recommend checking what is leaking (https://www.yourmechanic.com/article/how-to-diagnose-a-fluid-leak-by-mark-vallet) first. If you're doing the upper gasket it...
Oil leaked out, van ran hot and radiator had a leak oil was splattered everywhere and backed up into the coolant jug 2002 Ford E350 Super Duty
Hello - I suspect you will find blown head gaskets (https://www.yourmechanic.com/question/blown-head-gasket) based on the oil in the coolant" observation, with indications of extremely high pressure coming into the cooling system. Hopefully the determination you have that cylinder heads themselves were...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com