Dumb idea... or could I change my coolant like this?

[Lewy]

Right I know my coolant is a weak mix and want to change it. But dont want to drain out the whole system and have the worries of a poor bleed and re-fill so...

Could I extract the header tank fluid using my big oil change syringe and replace with good quality antifreeze and water mix. Then run the engine for a bit, stop and do it again top up again, run and circulate the fluid again, stop and...well you get the idea.

What do you reckon - good idea of complete idiotic ramblings?

[roosteruk]

It would work Lewy, but you would probable get the mix all to cock, not that it matters too much.

[shakey]

I upgraded my antifreeze strength last year after a RAC man topped up and bled the system with clear water. I loosened the bottom rad hose and SLOWLY let out enough liquid to nearly empty the header, then filled it with neat antifreeze. I repeated this until the darker green colour was obviously being let out at the bottom, when I stopped. Ran engine and then tested antifreeze strength. All O.K. and has been for past 13 months. Cannot remember how much antifreeze I used though. A bit lazy, but it worked for me Shakey.

[bigdaddycain]

Sounds good to me shakey

Surely ANY antifreeze in the system is better than none at all?

I reckon with a bit of judgement, the "density" of the colour of anti freeze will give a pretty good indication of the correct strength.

[roosteruk]

I reckon with a bit of judgement, the "density" of the colour of anti freeze will give a pretty good indication of the correct strength.

So does the taste, the sweeter, the stronger it is.
Don't swallow....

[Muzorewa]

......Don't swallow....

You're not kidding....

http://news.bbc.co.uk/1/hi/england/west ... 701360.stm

[Steve1259]

Wow that’s scary Muzorewa,
Lewy,
You will need to watch the mixture strength of antifreeze to water, if you end up with anything over 65% antifreeze – 35% water then the mixture starts to lose its ability to absorb heat. This means that your cooling system will not be as effective. We all know that these cooling systems need all the help they can get!
Steve

[Veg_Ian]

By changing the coolant in this way you are missing out on the opportunity to backflush the system. People get hung up on bleeding the Bongo cooling system. Yes it is important but in practice it's no big deal.

[Muzorewa]

Wow that’s scary Muzorewa,

As I recall from the time of the incident, in the absence of any other explanation the hospital presumed the guy had had a stroke and started treating him as such, with drugs to slow the metabolism - which apparently is the worst thing to do with a poisoning victim - hence the massive damage that was ultimately caused. I'm no medic but don't drink antifreeze!

I still drink Perrier, though

[dandywarhol]

Wow that’s scary Muzorewa,

As I recall from the time of the incident, in the absence of any other explanation the hospital presumed the guy had had a stroke and started treating him as such, with drugs to slow the metabolism - which apparently is the worst thing to do with a poisoning victim - hence the massive damage that was ultimately caused. I'm no medic but don't drink antifreeze!

I still drink Perrier, though

I seem to remember the Austrians having a taste for it in the 80s

http://www.weimax.com/austria.htm

[john and jue]

you could run the engine and disconect the bleed pipe under the passenger seat as the coolant goes down in the expansion bottle top up with 50/50 mix of antifreeze and water.dont let the expansion bottle run dry to avoid an airlock,connect bleedpipe and away you go

[Lewy]

What a great bunch of replies - thanks for all the thoughts - going to get on to it this weekend.