How to Replace a Radiator

by Contributor

Anyone with a bit of mechanical knowledge can replace a radiator on a car. Radiators need to be replaced periodically, usually because the hose necks tend to become brittle with age and break. Radiators can also be damaged by any kind of debris striking the front of the vehicle. While the exact radiator replacement process varies from vehicle to vehicle, the basic principles are the same on nearly all cars and light trucks.

Radiator Removal

Open the radiator drain plug, located somewhere near the lowest point of the radiator, and let the coolant flow into a catch basin to drain it. Loosen the lower radiator hose to drain the coolant if your radiator does not have a drain plug.

Detach the hoses from the radiator. Loosen the nose clamps and pull the hoses off of their attachment necks. Remove the auxiliary belts by sliding them off of their pulleys to gain more work room.

Remove the engine cooling fan and the radiator shroud. This step is vehicle-specific, and no single process will cover all types of engines. In most cases, you have to use a wide box wrench to release the mounting bolt that holds the fan to the engine. Set your cooling fan down upright to protect its clutch. Loosen the mounting hardware that holds the shroud. You might have to pull the fan and the shroud out together if clearance does not permit you to pull them out separately.

Remove any mounting screws, bolts, clips or other remaining attachment points. Put these pieces of hardware into a container so that you do not lose them.

Lift the radiator clear of the engine. This can result in a mess of coolant as the radiator shifts around, so have newspaper and a catch basin underneath the radiator.

Radiator Replacement

Slide the replacement radiator into place. Handle it gently so you do not damage the delicate cooling fins or hose necks.

Replace the mounting hardware. Torque them so you do not break the new radiator.

Reinstall the cooling fan and the shroud by simply reversing the fan and shroud removal process.

Reattach the cooling hoses to their mounting necks. Snug the hose clamps down, being careful not to over tighten. Consider replacing your cooling hoses at this time, as they become brittle and prone to failure with age. Replace them all if you replace one.

Install and tension the auxiliary belts if you removed them to get more room to work. Slide them back over their pulleys and adjust tension by turning the tension adjustment nuts and bolts.

Cooling Addition

Mix the replacement coolant and distilled water in the right proportions for your vehicle and your climate.

Pour the coolant into the proper fill area. Depending on your vehicle, you may pour the coolant directly into your replacement radiator, into your overflow reservoir or somewhere else.

Run the engine to allow the coolant to circulate and add more as necessary.

Bleed the air from the system. There will be a bleed valve somewhere in the system, although its location will vary from vehicle to vehicle. Open the valve with a wrench and watch for bubbles. You know your radiator replacement is done when no more air bubbles bleed from the system and your coolant is fully up to temperature.


  • check Have the right set of automotive hand tools ready before you begin to make the job easy.
  • check Consult your vehicle's repair manual before you begin work.


  • close Do not begin this job when the car is hot. You might get burned, and you might not be able to drain the coolant properly. Opening the system when it is hot could result in a steam release.
  • close Do not over or under tighten the hose clamps. Over tightening breaks the necks and under tightening allows coolant to leak when the system is under pressure.
  • close Automotive coolant is highly poisonous, but its sweet flavor makes it attractive to animals. Keep pets away from your work area and keep coolant sealed.
  • close Be careful working around a running engine. You can catch your clothes around the fast moving belts and fan.

Items you will need

About the Author

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