Step-by-step Guide: How to Burp Coolant System​

The coolant system of a car is like the air conditioning of the equipment and maintaining the right operating temperature is crucial. However, if there are bubbles in the coolant system, it will affect normal operation. So, learning how to burp coolant system is a very useful skill.

How to determine when to burp coolant system​?

Before having a look at the detailed steps of how to burp coolant system​, the first step is to determine when we should burp coolant system.

Temperature dependent performance

Coolant level condition

Abnormal sound

The sound of purring or running water in the engine compartment, especially when the coolant system is working (such as after the vehicle is started or while driving), may be the sound of air mixing with the coolant in the coolant pipe or radiator, indicating that exhaust may be required.

Preparation of how to burp coolant system​

Before burping coolant system, it is necessary to ensure that the vehicle has been sufficiently cooled to prevent burns. It is usually recommended to wait for the engine to cool to room temperature before operating.

Before we try to burp coolant system, firstly we should be familiar with the layout and working principle of the coolant system, especially the location of key components such as exhaust bolts, expansion water tanks, and radiators.

Moreover, some coolant may be discharged during the process, so it is necessary to prepare enough coolant for replacement.

And the following list shows the tools needed for burping coolant system.

1. Wrench: Used to unscrew and tighten components such as exhaust bolts and radiator covers.

2. Funnel: When adding coolant, the funnel can avoid splashing coolant and ensure accurate addition to the liquid storage tank.

3. Coolant: Be sure to select the coolant that matches the model and specifications recommended by the vehicle manufacturer.

4. Container: Used to collect coolant that may spill during the exhaust process to prevent it from polluting the environment or causing waste.

5. Gloves and goggles: To protect your hands and eyes from coolant sputtering, wear appropriate protective gear.

Step-by-step guide: how to burp coolant system​

Step 1: Find key components

Coolant reservoir

Found coolant tanks in the engine compartment. Usually it is translucent, easy to see the liquid level, and there will be a clear sign indicating that the coolant storage tank.

Exhaust screw or valve (if available)

Refer to the vehicle or equipment manual to determine the location of the exhaust screw or valve. These parts may be located in the radiator, the engine block, or somewhere where the coolant lines are connected.

Step 2: Tank burp operation

Carefully remove the lid of the coolant reservoir. Some LIDS may be loosened by rotating, loosening a little to release internal pressure before opening fully.

Observe the coolant in the liquid storage tank. If there are bubbles, gently squeeze the small water pipe connected to the liquid storage tank to encourage the bubbles to discharge into the liquid storage tank. During this process, the coolant level may fluctuate.

Step 3: Burp coolant system with an exhaust screw or valve (if available)

Use the prepared wrench to carefully open the vent screw or valve, just a little. At this time, there may be coolant and air flowing out together, allowing the air to escape naturally until there are no bubbles in the outflow of coolant. During this time, use a container to catch the coolant that flows out. When you see a steady coolant flow out and no air bubbles, close the exhaust screw or valve.

Step 4: Checking

After burping is complete, check the liquid level in the coolant reservoir. If the level is below the minimum marked line, replenish it with coolant compatible with the cooling system. Refill slowly to prevent bubbles from forming again. Put the lid on the coolant storage tank to ensure a good seal.

Factors to consider of how to burp coolant system

Factors to consider when burping coolant system

Firstly, remember to slowly open the radiator cover or expansion tank cover to release the pressure inside the system. Note that this step should be especially careful to prevent hot air or cooling liquid from hurting people.

Secondly, start the engine and run it to normal operating temperature. During this process, observe the flow of the coolant, and if bubbles are found to emerge, it indicates that there is air in the system.

Thirdly, the drain bolt at the bottom of the tank can be gently loosened to allow the air to drain along with some of the coolant. Pay attention to the discharge process until only the coolant flows out. Then close the drain bolt.

Fourthly, during the burping process, if the coolant level is found to drop, the coolant should be replenished to the appropriate level in time.

Check and maintain after burping coolant system

After the burping process is completed, the sealing of the coolant system should be checked to ensure that there are no leaks. If a leak is found, the operation should be stopped immediately, and the cause of the leak should be checked and repaired in time.

If the coolant is consumed too quickly after exhaust, there may be a leak in the system. Continue to observe whether the temperature of the engine is normal. If the engine is still overheating, it may be clogged inside the cooling system and needs to be cleaned or replaced.

FAQ of how to burp coolant system

1. What should I do if I find a leak when burping coolant system?

Once a leak is found, the first thing to do is to immediately stop the current venting operation, which prevents the spill from getting worse and reduces possible damage. Carefully examine the location of the leak to determine whether the leak is in a radiator, water pipe, water pump, connection, or other component. Mark the location of the leak and clean the leak area with a clean cloth or paper towel to get a clearer view and prepare for subsequent repair work. If the leakage leads to a decrease in coolant, an appropriate amount of coolant should be added in time to prevent the engine from overheating. However, please note that when the engine is running, do not directly open the radiator cover or liquid storage tank cover to prevent burns.

If the leak is not serious and cannot be repaired immediately, some temporary measures can be taken to slow the leak rate, such as using tape or sealant to temporarily seal the leak. While waiting for professional maintenance, you should pay close attention to the state of the engine, especially changes in the water temperature meter. If the water temperature is found to be abnormally high, the engine should be stopped immediately and turned off to prevent the engine from overheating and causing more serious damage.

2. How to determine if the coolant system needs to be replaced?

First, check the liquid level in the coolant tank. If the level is below the minimum marked line, it may mean that there is a leak in the cooling system or that the coolant is being consumed too quickly. At this time, an appropriate amount of coolant should be added and whether there are leakage points should be checked. If the coolant level continues to drop, and there is no obvious leak point, it may be that the coolant is gradually consumed or deteriorated during use, and it needs to be checked and replaced.

3. What does normal coolant color and smell like?

Normal coolant should be pink or green and odorless. If the coolant is dark or smelly, it may be that the coolant is aging or contaminated and needs to be replaced. Dark, cloudy, or precipitating coolant may indicate that the coolant has deteriorated and needs to be replaced.

Final Verdict

To burp coolant system by yourself may seem a bit complicated, but if you follow the right steps in this guide, you can ensure the coolant system is working properly, thereby protecting the engine and related components from overheating