- Unscrew the radiator and expansion tank caps. This can only be done on a cold engine. When the engine is hot, unscrew the cap until the first click (with a rag) and wait until the pressure drops.
- When draining the coolant, take appropriate measures. In some cases, it is not necessary to drain all the coolant. For example, when disconnecting the upper water hose or thermostat, it is sufficient to drain the liquid only to the height of the corresponding part.
- Set the heater control lever to the "WARM" position.
- Open the drain cock at the bottom of the radiator and remove the plug from the side of the cylinder block. Figure 120 shows the location of both plugs on a 2.0L engine. On a 1.6L engine, the radiator plug is in the lower right corner, as shown in Figure 120. The blocking plug is located approximately in the middle of the cylinder block on the front side.
Fig. 120. Location of drain plugs on the engine and the bottom of the radiator (shown for 2.0L engine)
- After draining the coolant, tighten the tap and plug. After draining the coolant, as part of a normal coolant change, flush the cooling system. To do this, insert a water hose into the radiator filler neck and run water through the cooling system until clean water flows out of the drain holes. To improve flushing, start the engine.
To fill the coolant:
- Check again if the drain points are closed.
- Prepare a frost-resistant composition according to the expected temperatures. Usually a solution of 50% water and 50% antifreeze is sufficient.
- Slowly fill the cooling system to the bottom edge of the radiator filler neck and also pour liquid into the expansion tank.
- Tighten the radiator and expansion tank caps.
- Warm up the engine to operating temperature and then let it cool down again. After a few hours, check the coolant level again and top up with coolant if necessary.
- Fill the expansion tank to the "FULL" mark. When the engine is cold, the coolant level in the expansion tank may be between the "LOW" and "FULL" marks.
[The text is quoted from the source website: TOYOTAMAN]