Every 40.000km (24.000mls) or every other year the coolant has to be replaced. A relatively simple job which can be done by yourself. Saves you some money and enhances the bond between you and your car; Jinba Ittai!
What do you need:
- coolant (about 6 liters (10 pints (UK)))
- one large phillips head screwdriver
- reservoir (or reservoirs) to hold the old coolant (you can also cut the side out of an old jerrycan)
- empty jerrycan to hold the old coolant
- some old rags/towels/paper to catch and clean spilled coolant
- watering can & water to flush the system
- optional, key 10 (or ratchet) to remove the catch tank
The engine holds about 6 liters (1.3 Gallons (UK)) of coolant. Although you won't be able to remove all of it you will need enough capacity to catch this.
Make sure the engine is cold when you start
In the underside in the middle of the radiator is the stop. Most cars will have an engine undertray. There is a hole in it so you don't have to remove it. My undertray is missing this makes things a little easier.
Simply place the catch can and undo the stop. Try to prevent it from falling into the can.
When you take off the radiator cap things will flow a bit faster
When the catch can is about halfway full replace and slide the other one under. Don't let it fill completely. This will ease emptiing.
If all coolant has drained replace the stop. And if your coolant is as dirty as mine fill with tap water.
Also fill the expansion tank to FULL
Drive the car (place radiatorcap!) and see if the temperature comes up normally. Return home and take some time off, paint the fence or whatnot, wait until the engine has cooled. Best/easiest is to continue the next day.
Tap all water. If necessary (really dirty) repeat. If you are satisfied (it is clear) you can fill the engine with 'real' coolant. I removed the expansion tank. You can't reach into it with a brush but I put in some gravel and some water. By shaking you can remove most of the dirt/grime. Flush until the water comes out clean.
A funnel comes in very handy when you are filling directly from the jerrycan.
Also fill the expansion tank to FULL.
Fit radiator cap.
Keep a liter / pint of coolant on hand the first few days. Some air might (will) bleed from the system which makes the level fall. Keep it from going under LOW. Fill if necessary. It should level off over time.
PS: check level on a cold engine. Level might be lower when hot. It will overflow into the engine bay when overfilled.