How to replacing engine coolant?

Replacing engine coolant with a tight schedule is the right thing to do to ensure the engine cooling system is working in optimum conditions. The recommended change intervals vary widely; some carmakers recommend to changing engine coolant every 30,000 miles, and others more. However, checking the maintenance schedule in your owner's manual book is the best option.

Over time, the engine coolant loses its anticorrosive properties and lubricating ability. In several cases, the coolant changes to be the mud and clogging the entire cooling system channel. To avoid these conditions, then at a certain time, we must replace the engine coolant thoroughly.

In this post, we will give you information on how to change car coolant. But before all of it, we need to prepare several tools and parts such as:

Antifreeze coolant (see your manual book for exact volume)
Soft water
Sealant or form in place gasket
Hand tools (pliers, screwdriver, etc.)
Coolant drain pan
Carjack and jack stands (optional)

So here they are, step by step, on how to change car coolant.

1. Open the radiator cap

The first step to replace coolant is open the radiator cap to let the air flows into the radiator. It makes the radiator coolant draining process will be easier. Don't forget to check the radiator cap condition, such as the pressure and vacuum valves.

2. Open the radiator drain plug (butterfly bolt) and drain the coolant

Low down to the bottom of the car and locate the butterfly bolt on the lower tank radiator. It is a draining plug for the coolant. Put the drain pan under the drain plug. Open the drain plug and drain the coolant.

3. Close and tighten the drain plug

After the coolant drained all and there is no coolant left inside the radiator, close and tighten the drain plug carefully. Be sure it is tightened enough, and there are no coolant leaks from this drain plug.

4. Open the drain plug for coolant on the engine block

Several car engines provide the drain plug to drain the coolant inside the engine block. Locate the drain plug and put the drain pan under the drain plug. Open the drain plug and drain the coolant. Wait until all the coolant drains entirely.

If your car does not have the drain plug for the coolant on the engine block, skip this step and move to step number 6.

5. Close the drain plug

Add some sealant, adhesive, or FIPG to the drain plug, then re-attach the drain plug to the engine block. Tighten the drain plug with the specific torque (Refer to the service manual book).

6. Fill the radiator with soft water

Fill the radiator with soft water. Pour the soft water gently until it reaches the radiator filler neck. It makes your radiator full of soft water.

7. Open the upper radiator hose connected to the radiator

Open the upper hose radiator connected to the radiator, but let the other side of the hose connected to the engine block. It purposes as a way to drain and replace the old coolant that is left inside your engine block.

8. Start the engine and let it runs in an idling rpm

Start your engine and let it runs in an idling rpm. While the engine runs at an idling rpm, add more soft water to the radiator. Just wait for the engine temperature to reach its ideal working temperature, so the thermostat valve opens.

As the thermostat valve opens, the coolant inside the engine will come out. Pour the soft water continuously until we see the coolant from the engine block is more clearly and changed by the soft water.

9. Fill the radiator with the antifreeze coolant

After we saw that clear soft water comes out from the engine block, change the soft water with the antifreeze coolant. Pour the antifreeze coolant appropriately with the recommendation volume from the service manual book. Or, you can wait until the antifreeze coolant comes out from the upper hose.

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10. Stop the engine and re-attach the upper hose

Stop the engine and re-attach the upper hose. Don't forget to add sealant to ensure that the connection doesn't leak.

11. Do the "air bleed" for the cooling system

After we attached the upper hose, add more coolant to ensure that the antifreeze coolant was enough to fill the cooling system. Start the engine and let it run at an idling rpm to bleed the air inside the cooling system. Wait until the radiator motor fan is spinning automatically.

See the coolant inside the radiator and add more coolant until it reaches the radiator filler neck. Do the same until you see the radiator motor fan is spinning automatically twice or three times.

12. Close the radiator cap and fill the reservoir tank

After the air bleed process was done, then close the radiator cap. After that, see the reservoir tank of the radiator. Clean it first, then fill the reservoir tank with the antifreeze coolant until it reaches the maximum and minimum levels.

13. Run the engine and recheck for the leaks

Well done, you have done changing engine coolant. Now run the engine and recheck for the leaks, mainly from the drain plug (butterfly bolt) on the lower tank radiator and the upper hose radiator.