Club 80-90 Forums

3L aint enough of any concentrate in a total coolant change.. the system holds nigh on 17L from dry......... most concentrates you are gonna need at least 5L to get there min 30% for summat like -20c... (different manufacturers spec different things, 50/50 not always required

Personally I wouldnt be mixing different coloured ones especially the really modern stuff.. seems there has been a few reacting with each other....

Hi there
Based on an overall coolant capacity of 16litres...3 litres is less than a 20% mix, not anywhere enough!
Most vehicle manufactures recommend 35-40% mix, which is I suspect the approx mix VW would have recommended for the wasserboxer when it was new. Unfortunately time has revealed that a higher consentration is preferable because of head stud corrosion and is recommended by the experts on here and other VW forums. Whichever way you look at it the garage got it wrong and the problem is worse because whatever they drain out will contain 20% approx mix. They need to add at least another 5 litres..and that in theory would still end up less than a 50% mix.
One last note! it is not good enough just to drain the old coolant out! because that leaves a considerable amount of old contaminated coolant in the system, the coolant needs to be thoroughly FLUSHED out so it runs clear water before adding new antifreeze. SEE;

http://www.brick-yard.co.uk/VehicleSpec ... freeze.htm

Thanks for the replies - I'll take it back tomorrow and ask them to sort it.

One more question, that I can't see an answer for in the wiki, is should there be any coolant in the top-up/overflow tank?

Yes... the top up tank should be half full (there is a min and max mark on it, but in practice it should sit on the max mark when cold)

Did they bleed the system? are they actually familier with the system (most, if not all, average garages wouldnt know one end from the the other on a T25...... I have seen so many "cock" ups) they aint like yer average car.. and thats where the average garage falls down...

Don't think they're familiar at all with the T25. I only brought it to them as they're my closest and my throttle cable had snapped. Wasn't much fun driving around with a steel cable in my left hand as an accelerator!!!

Didn't think flushing/changing coolant would be much of a job but I was proved wrong!

Pretty sure the reason most people recommend using a 50/50 mix is to get the corrosion protection. Pink or purple at that ratio is generally considered the best you're going to get

3 ltrs of AF for a complete change of coolant is too liitle. Should have been more like 7 or 8 ltrs! Check the WIKI and Mocki's guid to bleeding, etc.

System is 17.5ltr. Best corrosion protection and antifreezie properties are offered with G12 from Vw.

Unfortunately works out at aprrox 8 litres, (I'm sure that little bit less won't hurt!!) which even at trade prices worked out at £26 for me recently!!

If it's a recent rebuild test the sytem with plain water first n drain it out in case it leaks like one i di d a few years ago...

The VW G12 coolant was designed with an in-built corrosion inhibitor which was supposed to coat the internal metal components with a protective covering. This is why VW state that if you replace major internal components then you should replace the coolant. (As the new parts will not be coated by old coolant) In practice it is doubtful that these claims can be backed, and that the G coolants need replacing at a similar rate to any good quality coolant. With that in mind, unless you really like pink, then a standard coolant will be fine, and regular replacemet more usefull than the G12 label.
There is a way of testing the coolant with litmus paper to ascertain it's corrosion inhinbition qualities, as it gets more acidic as rust starts to form.

And the front heater core is bled by flow rate achieved above 2000rpm.