Coolant/antifreeze change, water drainage

[Toyotabrother]

Hello everyone,

Last week i did a coolant change on my Toyota Avensis -08 T25 estate.

Everything went well except that i could not open the water drainage on the engine block(see this part 9091009120).
And since i did not have a spare, i didn't try to force-open it with the risks that exist with that method.

I did obviously go trough with the coolant change with cleaning of the radiator, new coolant etc.

But my question is now, if a buy a spare part, and open the old one with force(in case it breaks i have a new one).
Will it drain out the new coolant i poored inside my car, or will it only remove the old coolant that the engine block during time has collected?

And how important is to actually drain the engine blocks during coolant changes?

Thanks in advance.
//M 
 

[Rosgoe]

If the drain tap on the block is located roughly in line with say halfway down the radiator then it will drain the coolant out the radiator to that level through the bottom hose as the head of coolant in the radiator will be higher than the drain tap on the block and it will also drain the header tank.

I wouldn’t worry to much about draining the block anyway  as you have got rid of the majority of the old coolant some of the coolant will have come out the block if you drained it out the bottom hose.

[Toyotabrother]

33 minutes ago, Rosgoe said:

If the drain tap on the block is located roughly in line with say halfway down the radiator then it will drain the coolant out the radiator to that level through the bottom hose as the head of coolant in the radiator will be higher than the drain tap on the block and it will also drain the header tank.

I wouldn’t worry to much about draining the block anyway  as you have got rid of the majority of the old coolant some of the coolant will have come out the block if you drained it out the bottom hose.

Cheers for your answer.

Further about the drainage plug.
Is the purpose of the plug to drain out coolant, or is it other liquids as well?

I've heard stories of people getting oil out during drainage, however that was not a normal healthy engine.

[Rosgoe]

1 hour ago, Toyotabrother said:

Cheers for your answer.

Further about the drainage plug.
Is the purpose of the plug to drain out coolant, or is it other liquids as well?

I've heard stories of people getting oil out during drainage, however that was not a normal healthy engine.

No just the coolant if oil is coming out with water means head gasket has gone or if the vehicle is an automatic some manufacturers add a oil cooler for the transmission inside the radiator which is separate to the coolant and sometimes these can fail usually the o ring seals, not sure if the avensis uses this system.