How much fluid is needed in a loop?

[Bubo]

Also with regards to flushing radiators, I'll probably get crucified for this but I don't bother flushing with distilled/deionised, I just use tap water I figure that since the water isn't endlessly circulating through the rad for extended periods of time when you flush it the chances of any significant deposits from the tap water building up are pretty much nil.

This. Tap water is not going to magically destroy your rad if it comes into contact with it because you've used it to flush the thing. If you are extra paranoid just do a final flush with de-ionized.

 

[TheCenturion]

This. Tap water is not going to magically destroy your rad if it comes into contact with it because you've used it to flush the thing. If you are extra paranoid just do a final flush with de-ionized.

This is what I did. Tap water followed by distilled. The tap water was warm. If it's too hot it could bend your fins.

 

[twist3d0n3]

This is what I did. Tap water followed by distilled. The tap water was warm. If it's too hot it could bend your fins.

que?

 

[no_1_dave]

I used boiling kettle water to flush mine.
Rad was too hot to touch so needed to hold it with an oven glove

 

[1kiwi]

1-1.5 ltr's as above. The last thing you need is to be slightly short.