How to Flush Cooling System in Jeep Wrangler

In 5 simple steps Flush Cooling System in Jeep Wrangler TJ, JK, JL, & JT

Many manufacturers have developed extended life coolants, one will question if the coolant can cool and protect your engine from overheating for a decade. Considering the corrosion and the damage to your machine can be permanent when you take very long without servicing your coolant. 

Experts agree that despite your Jeep Wrangler having a coolant with extended life is crucial to practice coolant maintenance regularly. When you service your coolant regularly, you increase the boiling point of your water, fight corrosion of your coolant, which wears with time. You also increase the freeze protection during the cold season and winter. 

Are you considering servicing your coolant, but you have no ideas on how to flush cooling system in Jeep Wrangler? You are in the right place because this article will give you step by step on how you can flush your Jeep Wrangler cooling system. Read on. 

What is a Cooling System? 

A colling system is a system designed by the manufacturer to keep your engine from overheating.  It works by circulating water mixed with a coolant on the engine. With time the mixture of water and coolant becomes mixed with rust and scale, damaging the cooling system. 

The Flushing cooling system removes all the contaminated coolant mixture and replaces it with another clean coolant and clean water.

How to Flush Cooling System in Jeep Wrangler?

Below are steps you can use to flush your coolant without special assistance. Also note that if you see a very dirty coolant, then drain 1 quart and add 1 quart of new coolant and use your jeep for few days and follow the DIY process of flush Cooling System in Jeep Wrangler by yourself.

Tools you must have to do it yourself

1. Choose the Right Antifreez Coolant 

Before you even start draining your cooling system, the first thing you need to do is choosing a suitable coolant. It’s vital to refill your cooling stem with a suitable coolant to have a cooling system that performs on your Jeep Wrangler. 

To get the suitable coolant, you need to understand the model of your Jeep Wrangler. The 2007-2012 Jeep Wranglers model uses the Hybrid Organic Technology (HOAT). From 2013 onwards model use Organic Additive Technology (OAT) COOLANT. 

It’s crucial to understand you cannot interchange these coolants; they can cause accelerated corrosion of your cooling system when mixed or even overheating of the engine. 

The popular HOAT coolants are readily available in stores or auto parts stores all around, while the new OAT is currently distributed through the dealership. Whether you plan to use the OAT or the HOAT coolant with two gallons, you can refill your cooling system. Remember only to use undiluted coolant. 

OAT comes in bright purplish color to avoid mixing the two coolants, while HOAT has a bright orange color.

Best OAT Antifreeze Coolant for jeep wrangler

2. Drain the Coolant 

How to Flush Cooling System in Jeep Wrangler

It’s crucial to ensure that before you start draining your cooling system, the engine is coolant as hot coolant can be dangerous it can cause severe injuries to your hands. For safe access to the radiator, you need to remove the skid plate. To do so, use the screwdrivers to remove the screws. 

The fasteners usually spin faster while loosened, and it’s advisable to put a flat screwdriver or anything flat to prevent the spinning. If your Jeep Wrangler is a new model, it has plastic push-pins instead of the older models with Scrivet fasteners. 

When removing the skid plate, you can take out the front grille to access the radiator. Start by taking out Scrivet fastener pins on the top of the grille and disconnect the indicator lamps. When you have the top of the grille loose, pull it outwards to loosen the lower clips securing the lower grille and set aside. 

Once the grille is out accessing the bottom of the radiator hose cock with a piece of vinyl hose on the passenger’s side.  

Have an empty can to collect the dirty, open the drain cock and start draining the coolant. Ensure your drain cock is loosened by ½ turn, which is enough to allow the coolant to drain.  

When you take the radiator and coolant expansion tank caps off, the air freely flows in, and the coolant will flow out faster. You are supposed to ensure the coolant expansion tank is empty while flushing your cooling system. 

To ensure there is no coolant left in the expansion tank, you can use a vacuum pump and pump all the remaining coolant or take out the tank and dump any remaining coolant. 

Alternatively, you can drain any coolant that could have remained by lifting the driver’s side of your Jeep with a floor jack. Once you are done draining the coolant in the coolant bucket, tighten the drain cock. 

3. Flushing the Engine with Water 

Despite the through ways identified above of draining the coolant out of two gallons, only one and a half gallons can drain. To ensure the other half is removed, you need to flush several times and flushing the extended coolant tank. 

You can use the regular tap water with a hosepipe, but it’s advisable to use distilled water as it contains no minerals. Fill the extended tank with 1/3 of stilled water and start the vehicle turning the heater fully on while ensuring the radiator’s cap is off while the car is not moving. 

Install the cap and let your Jeep for 10-15 runs to ensures it reaches its full operating temperature and let it cool until you can comfortably touch it.  

4. Draining the Water 

Once the radiant is excellent, you can drain the water, which is a mixture of the remaining coolant in the cooling system. Use the steps outline above on how to drain the coolant. You can flush several times to ensure the old coolant is drained. Remember, each flush, you will remove cleaner water as the coolant decreases in the system. 

While flushing those several times, ensure you run your Jeep for 10-15 minutes to ensure the heat cycle of a running vehicle is reached for maximum draining. You can opt to flush two to three times or until you get clean water from the cooling system. You will flush out water, a little will remain, and it will mix with the new coolant. 

5. Refill with New Coolant 

How to Flush Cooling System in Jeep Wrangler

You are done flushing the cooling system of your Jeep its time now to go ahead and start filling the cooling system with new coolant. Start by ensuring the radiator is well closed, then start filling in. Usefully concentrated coolant to ensure your Jeep gets maximum protection from freezing, corrosion, and overboiling. 

The 50/50 coolant does not offer the required ratio and thus interferes with the cooling system ratio, providing you with less protection, leading to engine damage and failure. The radiator usually accommodated an entire gallon of coolant, fill the second gallon on the extended tank until complete and tightly close the cap. 

Start the Jeep and let it run for 10 minutes to ensure it gets the thermostat to its average temperature, check the radiant and add more coolant, then install the cap. Check for any leakages, and if there are none, you can install the grille and skid plate. 

Now dispose of the old coolant responsibly. You can check your coolant level after two days of driving. If the level is lower, adding the remaining fresh coolant till full also enables you to burb any air that may be trapped in when you were refilling. 

Why do you Need to Flush and Replace Your Coolant? 

Here are some queries on why you may need to flush and replace your coolant? 


You can flush your cooling system and replace the coolant as your routine. You don’t need to wait till your coolant changes its color. Ensure you change your coolant within the recommended time by your automaker. 

Dirty Coolant 

When your coolant is dirty, it changes its color to brownish color. The turn of color indicates that your coolant is very dirty and needs to be changed. Dirty coolant can be harmful to your engine as it will increase corrosion and overheating of the engine. Don’t let your coolant get to this point to avoid problems cropping up on the engine. 

Coolant full of Junk 

If your coolant is filled with junk deposited on the radiator hose, it only means coolant replacement and flush are long overdue. When your coolant stays for longer without a change, it becomes acidic and starts eating the metals of the radiator on your cooling system. 

When you have unflushed coolant for a long time, it develops junk and debris, and then the debris is deposited along the hose pipe. The accumulated debris can clog the radiator’s hose pipe and other parts of the coolant system along with the engine. 

The clog may cause overheating your Jeep, which is why regular flush and replacement of coolant are essential.   

How Urgent is Coolant Flush Needed? 

Your Jeep Wrangler will not break down just because you haven’t had a coolant flush for a while. Instead of having junk or your coolant becoming dirty to the point of changing color, you need to have a flush routine. 

For a Jeep Wrangler to continue working effectively, you need to change your coolant after every 30,000 miles covered. If counting miles covered is not your thing, it is recommended to change it every two years. Sometimes your Jeep can go longer without flush but make it a routine to flush and replace the coolant regularly. 

Does Jeep Wrangler Have Specific Coolant? 

The two primary coolants are organic or inorganic, with different colors depending on the type of coolant. The colors are not always specific to the type of coolant, which can be not very clear if you are not keen.  

There is no specific coolant for a Jeep Wrangler because various Wrangler models vary with years. Check your Jeep Wrangler’s manual to understand the type of coolant used by the manufacturer, which is usually recommended. Different wranglers could be using different coolants. 

How Long Can a Coolant Last on a Jeep Wrangler? 

The latest coolants (OAT), also referred to as Organic Acid Technology, have a life span of more than five years. Understanding how long a coolant can last on your Jeep will entirely depend on the type of coolant you are using. 

Some coolants require frequent flush and replacement, while others can take longer. Check your Jeep Wrangler owner’s manual to understand better how often you need to change your coolant. 

Can Coolant Run Out? 

How to Flush Cooling System in Jeep Wrangler

It’s unlikely for coolant out because it is capable of lasting years. However, coolant can run out if you have a leakage on the radiator that you overlooked. The effects of coolant running out on your Jeep can cause damage to your engine and even rust. 

There is a percentage that coolant should not go below, and most of the time, f it gets below it, you can start to see some problems arising that you may have no Idea their causes. 

What is the Cost of a Coolant Flush? 

The cost of a coolant flush depends on where you are getting your coolant flush from and the type of car you use. Most auto shops have different changes, but the average coolant flush cost ranges between $20 and $115. The average price consists of the labor and the parts that may need to be replaced. 

Alternatively, flushing does not require special skills unless you have some parts that need to be replaced. You can buy the coolant and flush it all by yourself, it doesn’t take long to flush and refill with a new coolant, and you can save a few bucks. 


Your Jeeps cooling system needs regular maintenance like any other part of your car. Most people don’t take coolant flushing as a serious matter and thus can go for a long time. Having a regular freeze coolant flush protects your car from a high point, freezing, rust, and corrosion of your Jeeps engine. 

Flushing does not take long, and you can do it on your own or at your car’s maintenance auto shop. It’s Important to understand the type of coolant your car uses to avoid mixing the coolants. Always use the fully concentrated coolants for maximum protection.