7 replies to this topic

[Waynetbun]

Well just been refitting a new water pump etc, plumbed back in the rad also.
My question is... do you fill up the whole system through the rad or do you fill up through the thermostat housing? or both?
And what sort of ratio of water to anti-freeze is best?

[Disco Dan]

When you fiddle with cooling system, always a good op to flush the whole system and refill. If your mini is getting on a bit or has not been flushed in the past year I suggest using white vinegar - use a 50/50 vinegar - water mix and run car upto temp. Let it sit for about an hour or two even longer if really clogged up (Never overnight). Then empty out and flush with fresh water. Vinegar is preferable to mainstream ''rad flush'' treatments as it is less harsh while doing a better job! Also has added bonus of being quite smelly so you know if you still have some in your system just by licking your finger or sniffing it.

I found putting a garden hose on the heater matrix pipe in the cabin and letting the water flow out the top of the radiator to be very effective. Back flushes the radiator and the heater as well as clearing the block (if you remove the thermostat). If you use the bottom connector on the heater matrix and flush using the hose it removes all the air. To refill, just use the top of the rad - then run the engine with the cap off to remove trapped air. If you have trouble with air locks in your heater, you may have the pipes around the wrong way!

Ratio of antifreeze varies for the climate - about a minimum of 30% antifreeze to a max of about 50% for really cold climates (really cold meaning you actually see snow).

Edited by Disco Dan, 16 April 2009 - 07:02 AM.

[998dave]

Agreed and agreed.

Most manufacturers suggest 50/50 antifreeze to water. The antifreeze stops the water freezing, but also contains corrosion inhibitors to stop your cooling system rusting up.

Dave

[jaydee]

Yeah thats the point..dont let the antifreeze concentration below 30% due to freezing/verheating and corrosion issues, and use ethylene glycol based antifreeze.

EDIT: form a minumum of 1.2lt (30%) to a max of 2lt (50%) of antifreeze and top up with water

Edited by jaydee, 16 April 2009 - 08:38 AM.

[Waynetbun]

Excellent thanks for the advise.
but what's the best way to fill it up thou through the rad or the thermostat housing?

[Boycie]

You'll have a job filling it up while the 'stat housing is off.. It needs to all be in one piece, fill slowly through the radiator until it appears full.

Then run the engine until the level drops (when the thermostat opens) and continue topping up.

Leaving the rad cap off while you do it is a good idea but keep an eye on the temperature gauge. It may need the odd top-up after a few runs, that's just the air working it's way out.

[Waynetbun]

Cheers for the help & advise peps.

[Grayedout]

Make sure your heater controls are set to HOT when you fill it !!