i own vios too, if you don't wish to remove the reservoir then u can try this:

when u flush the radiator, flush the reservoir as well, the excess water will overflow from the top since there is no drain point... then close the radiator drain plug and fill with water..... starts the engine and run it for few minutes until the engine is really hot..... then remove the radiator drain plug and water will flow out and you can see the water in the reservoir will be sucked out as well

Yes, until you see the water inside is clear

Yes, off the engine... becareful when remove the drain plug, will kena your hand a bit...

I use only 1 litre + distilled water. But I think most people use 2 litre coolant.

Very hard to explain . you need to remove the stock air ram to reach the drain plug. Or you can jack up your front right tire, stretch your hand through the fender gap, bypass a pipe (I think is aircon pipe) then can reach the drain plug.... but if you got big hand and arm then susah abit

Air ram is the air intake pipe connected from the airbox and ends at somewhere near the fog lamp, black color one.


Esky is right, when engine is hot and u open the radiator cap then it will be like fountain

But what I meant is the process after that, meaning you have drain the radiator coolant and have refilled with water. Then you can warm up the engine again to become hot then remove the drain plug only. Of coz there are some chances of getting your hand kena hot water when removing the drain plug. Best still remove the reservoir which I never done before.

Yes, vios one made of plastic.

Yes, clockwise to tighten and anti clockwise to loosen.