How To Change Your Car’s Radiator

Photo:Attribution Some rights reserved by Brian ⚓ Hillegas

Proper radiator maintenance is crucial to keeping your car running at peak performance and for avoiding costly engine damage due to overheating. This job is usually not very difficult, however any home mechanic should have a Haynes or Chilton manual for their car handy in case of any difficulties.


  1. Find out if the replacement can be done without lifting the vehicle.Some radiators are removed through the bottom of the car and require a lift. Read the Haynes or Chilton manual for your car to find out if you’ll need to lift the car first.

    • If it is indeed necessary, read how to lift your car here.
  2. Take a look at the hoses and connections to and from the radiator. Squeeze the hoses to check for deterioration. If any hoses are swollen near the hose clamps or have soft spots or cracks, replace them. Replace hose clamps if they bind or will not tighten. Replace the thermostat since it’s cheap and you’re draining the coolant already.
  3. Notice if you have rust in the cooling system. If you feel a crunching sensation when you squeeze the hoses you probably have rust in the cooling system. The system will need to be flushedbefore filling with new coolant. There are kits to do this at your local auto part store, but if you would rather do it yourself follow this procedure:

    • Drain old coolant into appropriate container for disposal.(most radiators have a drain plug on the bottom)
    • Locate and remove the thermostat.
    • Locate and remove the upper coolant hose.
    • Insert garden hose into where upper coolant hose enters engine.
    • Turn on hose, run until water exiting system is clear.
    • Remove the coolant reservoir and flush it with water.
    • Drain all water and re-install thermostat and reservoir
  4. Drain old coolant into appropriate container for disposal if you haven’t already done so and remove the thermostat. Most radiators have a drain plug on the bottom.
  5. Locate and disconnect all hoses leading to radiator. Use penetrating oil on all hose clamps to avoid breakage/stripping. In some cars, there may be a transmission fluid cooler built into the radiator. If there are hoses running from the radiator from the transmission, be careful to catch the trans fluid that drops when you disconnect those lines (don’t reuse that fluid either). Be careful with all fluids as they are very toxic.
  6. Locate and disconnect the fan motor electrical connector and any other electrical connectors. Usually it is necessary to remove the fan assembly in order to remove the radiator. It should be bolted to the radiator directly. Use penetrating oil on bolts to avoid stripping/breakage!
  7. Look at your radiator. There should be no hoses, electrical connectors, and it should have sufficient clearance to be removed. If not, study the layout and think before disassembling anything else. Some other components may need to be removed like a top engine mount or the battery tray.
  8. Look at how your radiator is attached to your car.Usually there are braces bolted to the frame on top, and the bottom rests on rubber feet within an indentation. Remove the top braces (Use penetrating oil on bolts to avoid stripping/breakage!) and pull upwards on the radiator. If it comes out, congratulations! If not, don’t yank or pry. Study it and find the other bolts.
    • Some radiators and fans are removed as an assembly. Some also may require the a/c condenser be disconnected before the radiator can be removed.
  9. Remember that installation is the reverse of disassemble. Remember not to over tighten hose clamps. Go over everything you took off in your head! If you forget the fan motor connector or a tiny water pump bypass hose you can waste a lot of effort and time.
  10. Refill the cooling system with coolant when everything has been assembled. To do this, remove the cap from the radiator, fill until coolant is visible but a few inches below cap level. Start the engine (don’t rev or accelerate); the coolant level will lower as the engine sucks in coolant. Continue to fill with coolant until the level stabilizes then install and tighten the cap. Lastly, fill the coolant reservoir with coolant to the appropriate level. If transmission fluid was spilled, check trans fluid level and add new trans fluid if necessary.
  11. *Some engines have a special fill procedure or bleeding air out procedure. Follow the manufacturer recommendations for refilling.

Article provided by wikiHow, a wiki that is building the world’s largest and highest quality how-to manual. Please edit this article and find author credits at the original wikiHow article on How to Change a Car Radiator. Content on wikiHow can be shared under a Creative Commons License.

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