How To Replace a Radiator
Radiators get clogged and old, causing overheating and possible engine damage. This is how and why you should replace a radiator.
On a long enough timeline, random things start wearing out on every car. Fluids get old, seals dry up, and age can overtake even the most tender love and care. One of those random wear items is the radiator.
Over time, the metal and plastic of the radiator get brittle, worn, and deteriorated. If the proper coolant flush intervals weren’t observed, it might even rot from the inside, clog, and catastrophically overheat. Other times it causes a leak when the radiator splits from age and use. Either way, when the time comes to swap a radiator, it actually isn’t too hard to accomplish. All it takes is some basic tools and knowledge. If your car needs mending, and the radiator is the issue, follow these general guidelines to get your ride back in good shape.
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The Basics of Replacing a Radiator Basics
Estimated Time Needed: 2 hours
Skill Level: Beginner
Vehicle System: Cooling, engine
Doing this job can be messy more than anything. To ensure that no coolant goes anywhere that could be dangerous, make sure to have some safety glasses, gloves, towels, and make sure the car is cold when working on it. Do not do this job while the car is hot. Don't even open the radiator cap while the car is hot.
Everything You’ll Need To Change A Radiator
Then the tools you will need are also fairly basic. We don’t know what’s exactly in your toolbox so we’ll list what you need. Just in case.
- Coolant (of the correct type)
- Hose clamps
- Radiator cap
Organizing everything you need before starting the job will save precious time and frustration. Make sure the job can be done in one session and life will be easier. Trust me.
Here’s How To Change a Radiator
Most radiator swaps work similarly, even if they’re secured to the car in slightly different ways. Let’s walk through the general steps.
1. Locate the Coolant Drain/Petcock and Drain Coolant
Draining the coolant first allows the system to fully evacuate while you move on to other steps. Most cars will have a drain plug at the bottom of the radiator, but some do not. In that case, it is best to remove the lower radiator hose. It will cause a mess, but it’s the best way to drain the system. Once the system is done draining, remove the main upper and lower coolant hoses connected to the radiator. If there are transmission fluid lines, now is also the time to disconnect them, but avoid draining the fluid.
For more info on what to do with that coolant once it's drained, check out How To Get Rid of Toxic Used Car Fluids, Tires, and Parts Properly.
2. Remove Radiator Fan and Fan Shroud
Most cars will have the radiator in the very front of the car, save for some exotic cars. It will have a fan attached to it with a plastic shroud or have a plastic shroud and a fan attached to the engine. The radiator itself looks like a grid with extremely thin fins. Remove the plastic shroud and fan to get access to the radiator. They are usually held on by bolts on the top of the radiator or on the back of the radiator, but each car is different.
3. Remove Radiator
The removal of the radiator itself will be largely similar to removing the shroud. On some cars, the radiator is held in by two bolted brackets at the top of it, and it lifts out easily. Other cars secure the radiator with four bolts and the radiator must be angled out. Either way, take care to note anything that came out with the radiator, like rubber mounts or bushings.
4. Inspect and Replace Thermostat
While the radiator is out, it’s a good idea to generally refresh the cooling system. A new thermostat future-proofs the car against any strange overheating issues and replaces another major failure point that could leave you stranded. It’s generally located at the inner end of one of the coolant hoses in a bulbous housing. Most cars use a rubber gasket, though some call for sealant. Make sure to research beforehand. Some cars don’t allow easy thermostat changes. In those cases, disregard it as a maintenance item.
5. Reinstall Radiator and Fan Shroud
Installing the radiator is the exact opposite order of removing it. Make sure to take extra care to not damage the incredibly fragile fins of the radiator. Also make sure to align the radiator correctly in its mounts or bolt holes, otherwise there will be more fitment issues later in the repair. Once it’s home, reinstall the fan and shroud in reverse order.
6. Reconnect coolant hoses, refill, and bleed
Once everything is in place, reconnect all coolant hoses and reclamp them, making sure the clamps are straight and tight. Then refill the cooling system through the radiator cap or coolant reservoir until it takes no more coolant. Bleeding the system is simple on most cars but we have a detailed guide that will make sure that the bleed is done properly. It is the most crucial part of the install. Once it is bled, the car is ready to drive.
Pro Tips to Changing a Radiator
- Make sure to get a large, wide drain pan. Coolant gets everywhere and is not good for the environment. For more protection, you might want to put some cardboard or plastic sheeting underneath, as well.
- Do not mix coolant types. Refill the system with what came out of it, or commit to a full flush and refill.
- It is worth investing in hose clamp pliers that lock in place. Normal pliers do the job, but specialty pliers make it easy.
- Getting new coolant hoses isn’t strictly necessary. If the hoses are intact and flexible, they should be reusable. If they are swollen and mushy, replace immediately.
Some of us, including myself, learn better visually. So I a couple videos that demonstrate how to change a radiator in easy-to-follow formats.
FAQs About Changing a Radiator
You’ve got questions. The Drive has answers.
Q. Can you change a radiator without draining the system?
A. No, you cannot. The system must be opened to do the job.
Q. How long do radiators usually last?
A. A long time, generally. Age, use, and maintenance factor heavily, but they should last at least 10 years if not more.
Q. Will a new radiator help my car run better?
A. Not exactly. If the car was overheating and causing a limp mode, then yes. But an otherwise functioning car will not run better from a new radiator.
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