How to Replace a Radiator Hose
Radiator hoses can crack or burst for various reasons. The two main causes are old age and excessive pressure in the cooling system, which can be caused by a failed head gasket. Regardless of the reason, a broken or leaking radiator hose must be replaced as soon as possible. And you should never drive your car when you suspect a radiator hose is leaking. The good news is that replacing a radiator hose is a fairly quick and easy task that you can do at home.
How to Check Your Car’s Radiator Hoses
- Raise the hood of your car and secure it.
- Locate the two hoses, attached to the top and bottom of the radiator, that carry coolant to the engine.
- Inspect the hoses for visible signs of wear. If you see any cracking or swelling, particularly on the underside of the hose, it may be smart to replace it now before any further damage is done.
- Squeeze each hose. The hose should feel springy and flexible. If it feels weak and overly soft or brittle and hardened, you will need to replace it.
- Check the clamps. The clamps should be holding the hoses securely in place. They should also be free of corrosion. Adjust and replace them, as required.
Supplies You May Need
Once you have determined that you need to replace your radiator hose(s), it is important to gather the necessary supplies before you start your replacement project.
- Car Manual—It is always good to have your manual nearby when you are repairing your car, because there might be specific instructions that are helpful for your particular car.
- Sturdy Protective Gloves—Coolant is toxic, so you want to keep your skin covered.
- Safety Glasses
- Car Jack—If your car is low to the ground, it is recommended that you jack up the front to give you better access to the underneath side.
- Flathead Screwdriver
- Utility Knife
- Pliers—Needle-nose pliers work well, but other types can work if they are all you have.
- Drain Pan—It needs to be big enough to catch the coolant that will drain out during the process.
- Disposable Container—You will pour the old coolant into this for disposal.
- Fine Sandpaper
- New Radiator Hose(s)—Check your car manual to determine what type of hose you need. You can also snap a picture of it and show it to a clerk at your local parts store (you will also need to know the year, make, and model of your car). It is possible to only change one hose, if only one is damaged. However, it is recommended that you change both at the same time, to save yourself the hassle of having to replace the other one down the road.
- Hose Clamps—If your current hose clamps are in good condition, it is okay to reuse them. But they are cheap, so it is recommended to change them at the same time for the sake of longevity.
- Sealing Compound—This helps secure the hose to the engine and radiator fittings.
- Coolant—Again, check your manual to determine the right kind of coolant. You can also look in the reservoir to see what color it is. (Coolants are typically green, red, or orange.) You will want to use the same color as is already in your car.
- Distilled Water—You will need to create a 50/50 mixture of coolant and water. Tap water is acceptable, but distilled water is better.
- Old Towels or Rags
Before you remove or replace a radiator hose it is crucial that you observe the following safety precautions:
- Park your car in a safe and accessible location. You will need to have plenty of room to easily access the front and underneath of your car. You also need to ensure that coolant cannot drip into the ground or any storm drain.
- Ensure your car engine is completely cool to prevent the possibility of burning yourself. This may require you to plan ahead, parking an hour or more before you plan to replace the radiator hose.
- Wear gloves, safety glasses, long sleeves, pants, and close-toed shoes to ensure your skin and eyes are safe from any coolant drips or sprays.
- Clean up any coolant spills. Remember, coolant cannot drip or pour into the ground or down a storm drain. It also should not be left where a child or an animal could encounter it. So, quickly wipe up any drips or spills.
How to Remove a Radiator Hose
- Jack up the front of the car. Ensure it is secure before you proceed.
- Drain the coolant from the radiator.
- Locate the radiator drain valve. It should be on the underside of one of the radiator tanks.
- Center the drain pan under the drain valve.
- Remove the drain plug (petcock) and let the coolant drain into the pan.
- Pour the old coolant into the disposable container. Check with a mechanic about where you can dispose the coolant.
- Clean up any coolant spills.
- Remove the hose clamp. Carefully loosen the clamp with pliers. Then, remove it and set it aside.
- Remove the hose. Firmly hold the end of the hose and slowly try to turn and pull it off. If it does not slide off easily, you can use a utility knife to cut a slice from the hose end to the nipple it is attached to. Then, peel the hose back. (You may need to make a few cuts around the edge, if one is not enough. Be careful to only cut the hose.)
- Clean the hose fittings. Wipe away any stray coolant on the engine and radiator hose fittings. Then, use fine sandpaper to freshen the fittings so they will make a better seal with the new hose.
- Reseal the radiator tank. Insert the petcock back into the bottom of the radiator drain valve. Ensure it is secure.
How to Replace a Radiator Hose
- Double check that your new radiator hose matches your old one.
- Apply sealing compound to the hose fittings.
- Replace the radiator hose. First, place loosened clamps over the hose ends. Then, slide the new hose onto the engine and radiator fittings.
- Secure the clamps. Position each clamp so that it is approximately a quarter of an inch from the hose end. Then, tighten the clamp until it is securely in place. Do not overtighten or you may damage the radiator hose.
- Refill the cooling system. Make a 50/50 mixture of coolant and distilled water. Use the funnel to refill the radiator with the coolant mixture. Clean up any drips or spills.
- Check the cooling system. Run the engine for a few minutes. Inspect the hose connections to ensure there are no leaks. After the engine has reached its normal operating temperature, inspect the clamps to ensure they are still secure (both the clamps and hoses will expand as they heat up). Adjust the clamps if necessary. Drive the car around the block and then park and turn it off. Check under the car to ensure no coolant is leaking.
- Safely dispose of old coolant. Any of your old coolant will need to be disposed of properly. Check to see whether you have a local hazardous waste disposal place that accepts drop offs. You can also contact a mechanic or auto parts store to see if they can tell you where you can dispose of antifreeze locally.