Fixing a radiator is intermediate for most DIYers. Here’s everything you need to know to fix your radiator at home.
- DIY Difficulty Level: Beginner to intermediate. You need to have basic knowledge of the radiator, including how to drain and flush it. The difficulty level also depends on what is causing the leak.
- Time Required: If it’s your first time fixing a radiator, it may take you up to eight hours, while it would take a trained professional between two and three hours.
- Tools & Materials: Depending on the leak source, you may need the following tools and materials: drain pan, wrenches, pliers, screwdrivers, pressure tester, spare expansion tank, brake cleaner or degreaser, and epoxy.
What Is the Radiator?
Your car’s engine operates at extremely high temperatures, and the cooling system prevents the engine from overheating. There are many components to the cooling system, but it’s the radiator’s job to actually do the cooling. As the coolant heats up inside the engine, the water pump circulates the coolant through the cooling system, and the radiator lowers the temperature of the coolant by allowing the air to flow through its network of cooling fins.
Is It Safe To Drive With a Broken Radiator?
If you have a small leak in your radiator, you should be able to drive it for short distances at a time without suffering any damage (as long as you regularly top off the coolant level). With a larger leak or even a cracked radiator, you should stop driving immediately to avoid causing serious damage to the engine.
Small radiator leaks can be temporarily stopped using a coolant additive, but this is only a Band-Aid repair that should be used to delay an inevitable repair. Some shops exist that repair larger leaks or cracks in a radiator, but if your radiator is older, it makes more financial sense to just replace the entire radiator.
When To Replace Your Radiator
The only time you’ll ever need to replace the radiator is if it’s damaged or leaking. Checking the condition and levels of the coolant on a regular basis will help you keep a better eye on the condition of the radiator, and it’s a good idea to give your engine’s cooling system a good inspection at least twice a year, usually before summer and winter is best.
Radiator fluid or coolant should be changed out every 30,000 miles, but this can vary depending on the make and model of your vehicle. If you notice that your radiator is leaking or your vehicle is always running hot, it’s time to take a look at your radiator, whether you do that at home or take it to the shop.
What Are Common Symptoms Indicating You Need to Fix Your Radiator?
A few signs or symptoms to watch for when it comes to your vehicle’s radiator include:
- The temperature gauge shows your vehicle is running hotter than usual
- A puddle of green fluid is found underneath your vehicle
- Rust on your radiator
- Air in your cooling system
- Steam rises from under your hood
Keep in Mind
Please consult your owner’s manual for the manufacturer’s recommendations on regularly scheduled maintenance and repairs. Be sure to fix your radiator in accordance with the specifications for your exact make and model to ensure the best outcome. While this article shares the process for fixing your radiator as a DIY project, it’s highly recommended that you talk to a professional regarding your issue. You can contact Master Mechanics at the FIXD Mechanic Hotline for more information.
How To Fix Your Radiator
Flushing Your Radiator of Bad Coolant
Step 1: Before beginning any work on your vehicle’s radiator, you’ll want to let the engine cool completely (it’s best to the vehicle sit overnight before starting this job). Start by removing the radiator cap off to releive any pressure in the cooling system. USE CAUTION when removing the radiator cap while the engine is hot.
Step 2: Position a container or drip pan to catch the coolant under the radiator, and with the cap off, open the radiator petcock valve to drain the coolant.
Step 3: Using a hose, flush the radiator. You’ll want to close the petcock, fill the radiator with water, start the engine for a few minutes, and then drain the radiator again. Repeat this process two or three times until the water is clear of bad coolant.
Sealing a Leak in Your Radiator
Step 1: Replace the radiator cap, which may have become oxidized or full of grime, which wears the cap out.
Step 2: Use a commercial leak sealant. Most auto parts stores will sell a leak sealant as a temporary fix for a radiator leak. Be sure to top off your coolant levels after adding the stop leak.
Step 3: Fill cracks with radiator epoxy. If you can see cracks in your radiator, you can use epoxy to seal the crack. You’ll want to clean the area thoroughly, using either brake cleaner or a degreaser, so you can see what you’re working with for cracks. Apply the epoxy over the entire crack, and then let the vehicle sit overnight for the epoxy to set up.
Step 4: Replace the radiator. If your radiator has a significant crack or you’ve already tried to stop the leak and use epoxy, it’s time to replace the radiator. To replace the radiator, you’ll start by draining all of the fluids and disconnecting the hoses. Next, you’ll unbolt the radiator from the brackets; there are usually four to six bolts. Slide your radiator up and out of the vehicle, replace it with a new radiator, and secure the bolts. You may need to remove trim panels for body panels to get at your radiator.
Still Need Help?
If you want to speak to an expert about your radiator fix, or other issues with your vehicle, the team at FIXD Mechanic Hotline is ready to walk you through DIY repairs or answer any questions you may have. You’ll get unlimited access to Master Mechanics from 8 a.m. to 8 p.m. Monday through Friday with the FIXD Mechanic Hotline. Check them out today!
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