How To Change The Coolant In Your Car, by Engineering Explained on YouTube. 3 min 27 s.
- Video length
- 3 min 27 s
- Time to do it
- 45 minutes
- Difficulty
- Medium
- Steps
- 8
What you need
Steps
Let the engine and radiator cool completely before you touch anything. A hot radiator cap can spray scalding coolant, so check the warning label on the cap and wait.
Set the heater control to maximum heat. On modern cars with electronic controls, turn the ignition on first so the heater core valve opens and the old coolant drains out fully.
Check your owner's manual for the coolant specification, the total capacity and the replacement interval. Older cars often call for a change around 45,000 miles.
Put the drain pan under the radiator drain valve, open the valve and remove the radiator cap so air can push the coolant out. Open the engine block drain plug too if your car has one.
Close the drains once the flow stops. Flush with distilled water if the old coolant looks dirty, then refill through the radiator neck with your 50/50 mix using the funnel.
Squeeze the upper and lower radiator hoses a few times to burp trapped air, then top the radiator up to the neck.
Start the engine with the cap off and the heater on hot. Let it idle until the thermostat opens and the level drops, then top up again and refit the cap.
Run the engine until the cooling fan cycles, watch for leaks, then let it cool and recheck the radiator and the overflow bottle. Top up to the cold mark.
Tips and common mistakes
Never open the radiator cap on a warm engine, even if the hoses feel cool to the touch.
Do not mix different coolant types or colours, because some formulas react and turn to sludge.
Use pre-mixed 50/50 coolant, or distilled water with concentrate, rather than tap water.
Take the old coolant to a recycling centre or hazardous waste site. It is toxic and should never go down a drain.
Questions
How often should I change engine coolant?
Follow your owner's manual, since intervals range from about 30,000 to 100,000 miles depending on the coolant type. Old coolant loses its rust inhibitors even if it still looks fine.
Can I just top up the coolant instead of draining it?
Topping up is fine for a small loss, but it does not remove the worn-out fluid. A full drain and refill replaces the additives that protect the radiator and water pump.
How do I know all the air is out of the system?
Run the engine with the cap off until the thermostat opens and the level settles, then top up. The heater should blow hot air and the temperature gauge should stay steady.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
