How To Change A Car Radiator Yourself
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Changing car radiators is a satisfying DIY challenge
You can absolutely replace a radiator yourself. It’s a challenge, but with the right tools and some basic knowledge, an untrained layperson can do it without a mechanic.
Cars can be complicated machines, and your car’s engine bay might have hundreds of precisely fitted components. If your old or damaged radiator isn’t dissipating heat properly, it’ll cause engine overheating. All that heat can cause damage to important components.
If you’re going to replace your radiator yourself, you’ll need to make absolutely sure that all parts involved are safely and correctly removed and refitted. Keep in mind that changing a car radiator can take hours, depending on the vehicle and your level of auto repair experience.
Since you’re reading this page, you’re probably not keen on tackling this job yourself instead of getting a professional to replace your vehicle radiator for you. We admire your spirit. But if you change your mind, Natrad has radiator specialists who can look after this for you.
What you’ll need
The first thing you’ll need is your vehicle’s workshop service manual. This manual will give you a detailed description of your vehicle’s cooling system, so that you’ll know how to remove the radiator correctly, and which new radiator will be compatible with your car. It may even have model-specific instructions, which will be extremely useful for you.
If you don’t have your car’s workshop manual, you can usually find repair manuals at auto stores.
Tools you need to change your car radiator:
- Car jack (most cars come with one — check your boot) and axle stands (or a pair of car ramps)
- Wheel chocks
- Ratchets, sockets and extensions
- Wrench set (including line wrench)
- Screwdrivers
- Pliers
- Drain pan (a flat tub or container will do)
- Plastic funnel
- Drop sheets and shop rags
- Plastic sheets or plastic bags
- Coolant (if you are not reusing existing coolant)
- Muslin
- Protective gloves and safety glasses
Steps for changing a car radiator
We’re going to break up the radiator replacement process into four parts:
- How to drain the coolant from a car radiator
- How to remove an old radiator from a car
- How to install a new car radiator
- How to fill a new radiator with coolant and purge air bubbles
To begin, park your car on level ground in a well-ventilated and well-lit area. Access to the bottom radiator hose and low mounting points on the radiator may be easier to reach from underneath, so use ramps or a jack and axle stands to raise the front of the vehicle. Engage the handbrake and chock the rear wheels to prevent the vehicle rolling. Place drop sheets on the ground under the radiator and engine to soak up any accidental spills. Always wear your personal protective equipment to avoid personal injury. It’s also important to only work on a cold engine since you’re liable to burn yourself if you work on a hot engine.
Step 1: How to drain the coolant from a car radiator
- Jack up your car: Use your vehicle jack and axle stands (or ramps) to raise the car. Place chocks behind the tyres and secure your handbrake.
- Disconnect power at the battery: Undo the connections from the positive terminal of the battery to ensure there’s no electrical power running in the car. This will make it safer for you to work.
- Lift off the radiator’s fan shroud: The shroud can be removed using a wrench.
- Disconnect the radiator reservoir hose: This hose connects at the top of the radiator and leads to the reservoir. Carefully pry its connection to the radiator loose using pliers. Also remove the radiator cap.
- Disconnect the radiator lower hose: This hose is attached to the radiator near the bottom and is secured with a clamp. Place the drain pan beneath the radiator, then remove the clamp and pull off the hose. Once the radiator fluid has completely drained, set the pan aside.
- Store the coolant safely: You can reuse radiator coolant if it is not contaminated or degraded. If you intend to reuse the drained coolant, store it in a covered container to prevent debris polluting it. If the coolant is brownish in colour or cloudy, it should be disposed of – fresh coolant will be needed.
To dispose of old radiator coolant, take it to your local recycling centre in accordance with your local government regulations. Do not pour radiator coolant down the drain or onto soil.
Step 2: How to remove an old radiator from a car
- Remove the electric cooling fan: First, unplug the cooling fan electrical connector. Then, remove the cooling fan mounting bolts. The fan should then lift out. Set it safely aside.
- Disconnect the upper radiator hose: The upper and lower radiator hoses are also known as the inlet and outlet hoses. They may be secured to the radiator using hose clamps or spring clips, which you can undo using pliers or a screwdriver.
- If necessary, disconnect the cooler lines from the radiator: Cooler lines, (also known as transmission cooling lines), are long, thin metal tubes that connect your radiator to your transmission. They are often found in automatic vehicles, though not all vehicles have them.
- Secure the oil lines: Wrap plastic sheets or bags around the oil lines and secure them with tape or rubber bands.
- Disconnect any other components attached to the car radiator: In some car models, the air conditioner condenser is attached to the radiator. If this is the case, leaving the condenser hoses connected, you can loosen the condenser mounting fasteners with a wrench and lift it carefully out of the way. Your radiator may also be connected to various electrical components or sensors. Unscrew, unplug and detach all of these carefully.
- Undo the radiator mounting bolts and lift out the radiator: Place the radiator safely to the side. Use a dry cloth to wipe away any debris and mop up any spilled coolant.
Step 3: How to install a new car radiator
- Secure the new radiator to its mounts: Place the new radiator into position and tighten all mounting bolts with your wrench.
- Attach the AC condenser (reverse process of removal)
- Attach the oil cooler lines (reverse process of removal)
- Replace the fan and fan shroud: Tighten the mounts and ensure the fan is secure.
- Plug in the cooling fan electrical connectors
- Connect the upper and lower radiator hoses: Slip the mouth of each hose onto the radiator connection. Then, tighten the hose clamp as securely as you can using pliers.
- Connect the reservoir hose: This radiator hose can also be secured with a hose clamp.
Step 4: How to fill a new radiator with coolant and purge air bubbles
If you intend to reuse the coolant you saved from your old car radiator, you should filter it first. To do this, strain the coolant through muslin cloth to catch any debris.
If you are using fresh coolant concentrate, must be diluted with distilled water to the correct ratio (specified on your coolant container). It is critical that you use distilled water, as plain water (such as tap water) can contain mineral salts which can cause scale build up within your engine cooling system. Salts can also reduce the performance of corrosion inhibitor chemicals in the coolant.
Fill the radiator with coolant until it brims.
Air bubbles trapped in your radiator system can cause hot spots, which are points of extreme heat within the cooling system , that can result in damage. You need to ensure that air bubbles are removed from your system.
Start the engine and be ready to add more coolant into the radiator. You may notice that coolant will begin to sputter or ‘burp’ out of the radiator filler neck. Continue adding coolant to keep the level brimmed. When no more bubbles appear, fit the radiator cap.
Let your car run for 20 minutes, and monitor the coolant volume levels for consistency. Use your dashboard gauge to check that the engine temperature is safe and steady. Inspect for any coolant leaks. If all is well, you can take your car for a short test drive to see how it performs.
Frequently asked questions
What is the weight of a standard car radiator?
Empty car radiators can weigh from around 315 kg.
A radiator’s weight and dimensions will differ by make, model and materials used, as well as by the type of vehicle it’s designed for.
How do I measure a car radiator size?
Measuring a car radiator is quite simple — no different from measuring the dimensions of 3D objects in middle school.
If you’re planning on replacing your car radiator, you’ll need to ensure your replacement radiator can fit within the dimensions left by your old one. You’ll need to measure the old radiator’s height, width and thickness.
- Height should be measured top to bottom. Depending on your radiator, the height value might be shorter or longer than the width value.
- Width should be measured horizontally across the radiator face.
- Thickness should indicate the thickness of the core, even if the end plates are slightly thicker.
- Also note if the tanks are top and bottom or on the sides.
If you want to double-check your work before making a purchase, feel free to give us a call. We can help you determine the correct radiator for your vehicle and confirm its dimensions.
Do you have any advice on what size radiator I should get for my car?
We recommend you select a new car radiator that meets or exceeds the original equipment specifications including size, correct mounting fittings (and transmission cooler if required). If the vehicle is used in demanding conditions, a higher performance radiator may be required.
Can you drive a car without a functioning radiator?
Yes, but only for a few minutes taking care to stop before your engine overheats. If your radiator isn’t working, you should only drive your car for two reasons:
- To move it to a safe location, like the emergency lane, a car park or to your driveway.
- To get it to a nearby mechanic who can repair its radiator and cooling system.
If there’s a Natrad store near you, you may feel comfortable enough to drive to us. Keep a close eye on your engine temperature gauge to make sure it’s not overheating. If it does, turn the engine off for a few minutes to let it cool down.
Natrad excels at car radiator replacement and repairs
If you’d rather not bother with all the hassle, get in touch with Natrad. Our specialists will conduct a free cooling systems check and advise the best remedy to restore your car to good health. We guarantee our replacement radiators with a 3-year nationwide warranty, so you’ll drive away with total peace of mind.
