DAN76

After a complete flush out, how much coolant fluid should be put into the system on a 425 and what ratio of coolant to water is recommended?

Jamesbo

My stuff says 50/50 on the bottle.

joe_padavano

Are you using imperial gallons or US gallons?

Seriously, I just fill with 50/50 mix until the radiator is full, let the air bubble out, top off, cap, and run the engine until the thermostat opens (the upper radiator hose will get hot). Shut off, cool down, and top off again.

DAN76

cheers!
do you know the correct measurement of mixed fluid that should go into the engine or is it just a case of eyeing it up to the rad cap?

Lady72nRob71

Greetings to England!
It will be between 16 and 20 litres if you pulled the block drain plugs, but eyeing it is the best. If you did not pull the block plugs (or if you do not have any) then you will put in quite a bit less.

If there is no overflow bottle, I think the right level will be 1-2" below the fill cap to allow for expansion. If you do have the O/F bottle, fill up all the way and fill the bottle to the full mark.

Use 50/50 and you will be fine.

DAN76

sorry Jo i think our posts crossed over there.

Cheers guys!

Oh, one other thing... do you use de-ionised water ?

Yellowstatue

I use distilled water from the drug store or clean water from my de-humidifier in a 50/50 mix...cheers

Olds64

I usually just use tap water. IF changed regularly it shouldn't have much of an effect on your cooling system. Of course, if I had a $1200 Griffin 3 core radiator I would use distilled water.