How To Replace The Radiator, Hoses, And Thermostat

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The hot weather can put a lot of pressure on your engine's cooling system and can cause leaks to appear in your radiator. The only real option you have to fix the cooling system is to replace your radiator, and you should also take the opportunity to replace the old hoses and thermostat at the same time. Fortunately, changing the radiator, hoses, and thermostat isn't that difficult on most cars, and the average do-it-yourselfer can do the job in an afternoon. Here is how you can replace the radiator, radiator hoses, and thermostat in your car.

You Will Need:

Drain Radiator Fluid

You need to remove the fluid in the cooling system before you can remove the radiator. Engine coolant is now considered a hazardous material, and you cannot just let it drain onto your driveway and flow into the street.

Place a container under the drain valve at the bottom of the radiator and open the valve. If the coolant has rust and debris in it, you'll want to dispose of it and get new fluid to add into the new radiator (you should also flush out all of the old coolant if it's rusty and discolored).

Replacing Radiator

Disconnect the hoses at the top and bottom of the radiator. These are held on using hose clamps. You can loosen the hose clamps with a flathead screwdriver. Pull the hoses off of the radiator. If the hoses are feeling spongy, you should replace them with new ones.

You may have to remove the radiator fan to create enough space to lift the radiator out of the engine compartment. There are normally two bolts that have to be removed at the top of the fan. You also need to disconnect the electrical wire harness running to the fan. Lift the fan assembly out and set it aside.

Remove the bolts holding the radiator to the front of the car's frame, and lift the radiator out. Slide the new radiator back in and bolt it in place. Make sure the drain valve on the new radiator is closed.

Reinstall the fan assembly and reconnect the electric wire harnesses. Reconnect the bottom hose to the radiator and engine block with hose clamps.

Replace Thermostat

Before you replace the top hose, follow where it connects to the engine block. This is where the thermostat is located. Old thermostats often stop opening and closing like they should, and this causes damage to the engine block (old thermostats should be replaced every year or two).  A good time to replace the thermostat is when you already have everything apart.

Unscrew the two bolts holding the thermostat cover to the engine block. The thermostat should lift right out, but if it doesn't, pry it loose with the flathead screwdriver.

Put the new thermostat in according to manufacturer's instructions, and replace the cover. Then reconnect the top hose to the radiator and thermostat cover with hose clamps.

Refill Coolant

Pour the new coolant into the radiator, and turn the car on. The thermostat will open once the engine heats up. The fluid will drain out of the radiator to fill voids throughout the coolant system. Keep on pouring fluid into the radiator until it stays full.

Replace the radiator cap and periodically check for leaks in the systems.

If you feel you can't do any of the following steps, a local auto repair shop will be able to assist you, or click here for more information about auto services.