Club 80-90 Forums

Hi All - My van recently came back from the garage after having a new exhaust system upgrade and my carb refurbished, it also had a full MOT.
I noticed this morning that the water coolant expansion tank behind the number plate is empty, the main tank in the engine bay is full.
I''ve checked the hoses and expansion tank as best as I can and can''t see any obvious leaks, so i''ll move ahead with topping it up and see if it lowers.

But before I do so, i''ve read that it''s not a good idea to mix the different types of anti freeze. So how do I go about finding what type is or has been used in my engine?

And is there a type of anti freeze I can get from Halfords that you would suggest?

Hi Nath,

It should be G12 onwards. I bought my coolant in local VW main dealer and they said that thier latest stuff G13 + is backwards compatible for top ups or a full replacement.

Also, your main dealer prices should be on par with Halfrauds, if not cheaper as a service item.

First off, what colour coolant is in the expansion tank?

The expansion tank is bone dry empty and no residue left to be able to tell what colour.
I guess I could try to get a sample out of the main reservoir to see its colour.

Clear - it is air!
That's the trouble with calling the the tank that the coolant expands into the expansion tank and not the top-up tank.

Nathanb wrote: I noticed this morning that the water coolant expansion tank behind the number plate is empty, the main tank in the engine bay is full.

Shucks - replied whilst I was typing!

Okay so I managed to pipette some coolant out of the tank and it's green in colour

Who put that in then

The correct stuff is pink/red/purple(ish) and is to G12, G12+, TL 774 or G13 spec.

Read all about it in our wiki HERE

Green was/is the original VW spec for iron block, alloy head inline engines iirc?
Make sure its well flushed out with clean water or the mixed coolants will make a nasty brown tar, then you will need a new overflow tank because its murder to clean off.

For pink coolant I use the (confusingly numbered) Comma G30 but make sure that you havent got any "furry" hose connections or it will find its way out.

silverbullet wrote:For pink coolant I use the (confusingly numbered) Comma G30

That is what I use. The spec is correct. Quite reasonable price at Euro Car Parts stores.

Ian, would you have to fit new white tank(s). Surely a good clean would be sufficient?

Nathan, as Ian says, a good flush will be required, but the easy way to do that is drain down as much as you can, then fill up with plain water, drive it around for a day or two (or a few miles), drain it down and repeat a couple of times until the water is perfectly clear, then fill up with 50/50 correct type antifreeze ( / corrosion inhibitor). By the time you have done ^^^ you will be an expert at T25 coolant system bleeding .

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Years ago when my system got heavily contaminated with oil, I did as I describe above maybe 15 times in two weeks before it ran clean.
It gets easy after you have done it a couple of times. I got so I could do the whole job, drain, fill, bleed in about 15 minutes

I've got a bleeding tip for you. After the initial bleed of air from the rad and stat housing, let the engine warm up and then carefully loosen the rad bleed screw, just a turn or two. The normal pressure in the (warm / hot) cooling system will force any air out, but take care not to undo it too much that it comes out, or that same pressure will send a jet of very hot water all over you. This tip makes all that re-doing the "rev it up to 2,000rpm bit" not required.

John. I gave up trying to clean the brown goo out of the tank in the end, nothing seemed to shift it, petrol only softened it a bit (must admit that I didnt try brake cleaner)

silverbullet wrote:John. I gave up trying to clean the brown goo out of the tank in the end, nothing seemed to shift it, petrol only softened it a bit (must admit that I didnt try brake cleaner)

Right, that's pretty serious stuff then. Imagine all that stubborn goo in your rad and heater rad, not to mention water jacket etc
A simple mistake on coolant could end up a very expensive mistake!!

I've just remembered Nathans post title = "Coolant - Expansion tank empty"

So, bearing in mind what I said about draining down and filling with plain water a few times to flush, before putting the correct stuff in, then this is a doubly good idea because one must wonder why the top up tank is empty. Running for a few days on plain water, whilst monitoring the situation, potentially could save wasted money on loosing coolant with red antifreeze in it. Good job the freezing temperatures are behind us now. I hate it when this sort of thing happens in the depths of winter when you simply can't ever run with no antifreeze in

silverbullet wrote:John. I gave up trying to clean the brown goo out of the tank in the end, nothing seemed to shift it, petrol only softened it a bit (must admit that I didnt try brake cleaner)

Easy - gravel and washing powder and shake like hell, soon cleans the tank! (+Some water.)

It was like self adhesive tar. Weirdly all the gunge was near the coolant level sensor so maybe that circuit has something to do with it, electrolytically speaking?
The overflow was clean amd I found no sign of it when the engine blew (ran a big end)