coolant question

[woody]

Hello guys wondered if anyone has the perfect simplest way to drain coolant and then replace with new. Do I do this via the rad drain off point/will this drain the whole system, unsure? And also will it need bleeding/ will it bleed itself and what ratio of coolant/antifreeze to water should I mix. Not using pre mixed due to price. So I have 5litres of concentrate to mix. And also what is the complete volume of coolant needed to fill the system. Heard controversy on all of these questions so thought I'd put it to the expertise of the oc. Cheers any help/ guides be helpful

[Tom]

That plug on the bottom of the rad would drain quite alot i imagine. Can always take the thermostat out and flush the block through with water. It does need bleeding, loads of threads about that.

[Toms306]

Yes, drain by the rad drain point, it's the lowest point on the system.

Unfortunately the 306 isn't self bleeding so you will need to bleed it, this is a bit of a pain and requires you to make a header tank from an old coke bottle or similar.

The ratio should be written on the bottle....it's probably about a 3rd antifreeze to 2/3 water for winter temps.

5 litres of concentrate is more than enough. The whole system on a GTi is 7.5l.

[Grant]

That will drain the most from the system you can. There will obviously be points where water will sit still, but not loads.

[woody]

Is crafting a coke bottle over the header a kind of way of getting coolant to a higher point over the system so the weight of water forces out the air allowing all the coolant in and all the air out?

[Toms306]

Yep.

[cully]

coke bottle works a treat by far the easyest method

fit bottle
fill with coolant
open bleed points till flow close
start car run till fans run
keep topping coke bottle
keep bleeding at each bleed point
when no more coolant is drunk and fans have cut in
wait to cool
empty coke bottle replace cap

[attachment=13096]

[Martin306]

I mix mine 50:50.

It's not just an antifreeze, it's a coolant as well! So it's for all year round.

Coke bottle is best way, might need a bit of electrical tape on the neck though just to help it seal a bit better. can make a bit of a mess otherwise.

[woody]

OK I kind of got the idea. Well I will probably post a thread in projects soon with some pictures as most people won't remember when I joined I was planning on keeping my 6 standard/classic. But however that went out the window and mods have begun in the shape of track preperation so lots of work over the last few months and lots more to do. Will post some pix soon

---

Thanks for all that guys great PIC too fully understood now although where are the main bleed points?

[woody]

Where are the main bleed points and is there any danger running the engine up to temp so the fans come on with the coke bottle in place

[cully]

bleed points
1, N/side top of rad
2, socket screw top of thermostat housing
3, rubber flex tube where heater matrix pipes enter bulk head

and no it wont matter running without the cap and with bottle installed

[woody]

Cheers Cully most appreciated. This is why I love you guys, once again top advice from technical corner at oc. Awesome

[John1.4]

just to add, i've found that if you don't tape the drain pipe from the rad neck to the bottle, then the bottle empties itself onto the floor

[Tom]

I've always found the weight of the bottle seals it onto the rad

[Piggy]

Also I be surprised if it didnt have issues trying to run it up to temp without the cap on...