Coolant Replacement (K20C1) - Honda Civic FC/FK 2016-2021

Coolant Replacement

NOTE: How to read the torque specifications.

1.	Expansion Tank Cap - Remove

2.	Engine Undercover Plate - Remove

3.	Engine Coolant - Drain

Loosen the drain plug (A), and drain the coolant.

After the coolant has drained, tighten the radiator drain plug securely.

4.	Expansion Tank Coolant - Drain

5.	Engine Coolant - Refill

Pour Honda Long Life Antifreeze/Coolant Type 2 into the expansion tank (A) to the MAX mark (B).

NOTE:

Always use Honda Long Life Antifreeze/Coolant Type 2 or Honda Extreme Cold Weather Antifreeze/Coolant Type 2. Using a non-Honda coolant can result in corrosion, causing the cooling system to malfunction or fail.

Honda Long Life Antifreeze/Coolant Type 2 is a mixture of 50 % antifreeze and 50 % water. Honda Extreme Cold Weather Antifreeze/Coolant Type 2 is a 100% concentration coolant. Do not add water to either coolant.

If the vehicle is regularly used in very low temperatures (under ? 22 °F (? 30 °C)) a 60% concentration of coolant should be used.

Operation	Vehicle Usage (Desired Mixture)	Current Mixture	Coolant Drain	Add Amount of Honda Extreme Cold Weather Antifreeze/Coolant Type 2 (100% concentrate)	Then add Honda Long Life Antifreeze/Coolant Type 2 (50/50)
Coolant Change	Normal Area (50/50)	50/50 60/40 unknown	Drain radiator and expansion tank	None	Top off the cooling system
	Very Cold Area (60/40)	50/50 unknown	Drain radiator and expansion tank	About 1.6 L (54 fl oz)
	Very Cold Area (60/40)	60/40	Drain radiator and expansion tank	About 1.0 L (32 fl oz)
Engine Overhaul	Normal Area (50/50)	-	-	None
Engine Overhaul	Very Cold Area (60/40)	-	-	About 1.6 L (54 fl oz)
Coolant Winterizing	Very Cold Area (60/40)	50/50	Drain about 2.0 L (68 fl oz) from radiator	About 1.6 L (54 fl oz)
Coolant Winterizing	Very Cold Area (60/40)	unknown*	Drain radiator and expansion tank	About 1.6 L (54 fl oz)

*: When you want to winterize the coolant with the minimum amount of coolant change but the current coolant concentration in the vehicle is unknown, you must drain all coolant from the cooling system.

Engine Coolant Refill Capacities (Including the expansion tank capacity of 0.8 L (0.21 US gal))
At Coolant Change	4.7 L (1.24 US gal)
After Engine Overhaul	8.1 L (2.14 US gal)

6.	Engine Coolant - Air Bleed

Loosely install the expansion tank cap.

Start the engine and let it run until the radiator fan comes on at least twice. Do not operate the air conditioning system.

Turn off the engine. Check the level in the expansion tank, and add Honda Long Life Antifreeze/Coolant Type 2, if needed.

7.	Engine Coolant Leak - Check

Put the expansion tank cap securely, then start the engine again, and check for leaks.

Clean up any spilled engine coolant.

8.	Engine Undercover Plate - Install

9.	Maintenance Minder - Reset (With Maintenance Minder System)

If the Maintenance Minder required to replace the engine coolant, reset the Maintenance Minder with the gauge (see "Resetting the Maintenance Minder"). If the Maintenance Minder did not require to replace the engine coolant, reset the Maintenance Minder with the HDS (see "Resetting the Individual Maintenance Items").