Refilling cooling system

[aerosilver]

Hi all,

My engine's all back together and I am about to refill the cooling system (30% mix, deionised water). I've read the tip about cranking up the front near-side as high as possible to minimise trapped air, but once the system's been filled, should it be run with either the expansion bottle cap or rad filler plug off to help expel further air, or just put the lids backon and go for it?

Cheers,

Bob.

[dogsnadgers]

imported post

I just fill it, run fora bit until the thermostat opens and keep checking the level untilI amhappy it is full andany airlocks have been pushed out. Don't forget to open the heater controls to hot. Good Luck


Dave

[RogerP]

imported post

aerosilver wrote:

Hi all,

My engine's all back together and I am about to refill the cooling system (30% mix, deionised water). I've read the tip about cranking up the front near-side as high as possible to minimise trapped air, but once the system's been filled, should it be run with either the expansion bottle cap or rad filler plug off to help expel further air, or just put the lids backon and go for it?

Cheers,

Bob.

Hi Bob

The way I've always done it is a bit long winded but have never suffered from air locks....................Make sure the heater valve is open then slowly fill radiator through brass bung on rad to the top.............Thenfill expansion bottle3/4 full put cap back on expansion bottle, but leave top of radiator, now run engine up to temperature' you will probably get air and water coming out making sure you keep the rad full, when your happy it's up to temperature put the bung back in radiator and take the cap of the expansion bottle, then go for a little run say 2 miles, when you get back just make sure the bottle has got plenty of water in a keep an eye on it as it cools down it will go down. I leave it overnight to go completely cold, then empty the bottle to about 1/4 put cap back on top up rad if required.....I believe doing it that way you get rid of all the air and it's more able to suck the water back in.

Roger

[Sheepdip]

imported post

Agree with all comments so far with one addition from experience. Measure the amount of coolant you add to ensure it seems about right. I fitted a new thermostat to a rebuild which didn't have an air hole, resulting in partial filling with air lock in engine. I didn't realise as just stuck a hose in the filler and left it running as it warmed up. It blew an inlet gasket.

Paul.

[aerosilver]

imported post

Thanks guys, will try Roger's method at the weekend and report results!

Cheers,

Bob.

[stag74red]

imported post

Hi, another check:

put the front of the car up on ramps - I can get almost get anotherpint in.

I also move the expansion bottle up as high as the hose allows, then refited when engine cooled.

Mark.