Disco 2 Coolant - Cool or not Cool to mix brands (help!)

Hello - I'm keen but not experienced - can you help?!

Just done a check on my Disco 2 and coolant looks quite low. I don't know what brand was used in the last top-up and have just bought some Comma antifreeze. It struck me that I may not be able to mix and match.
Do I need to drain current liquid and replace? And is the fact that it is low a problem (a strange gurgling sound can be heard from time to time when I drive it) or is that normal?

Hope someone can help - there is so much advice on the internet I thought I would come to the experts.

Thanks in anticipation.

Mixing brands shouldn't be a problem if it is the same stuff but NEVER mix different colours. They can mix and create a corrosive substance. If you don't know what went in it last, it's best to drain the system, give it a good flush with water then use new stuff and keep a note of what you've put in.

When you flush, be sure to have both heater dials on full to open up the heater rad. Best to run a hose through for a while then fill up system with water. Start engine, mix it round and flush again.

Some people will say that's ott but imo it's best practice.

Ok Thanks for the prompt advice. I'll check the colours and if they match just go ahead. Otherwise, my next task will be working out how to flush the system!

DiscoPixie said:

Ok Thanks for the prompt advice. I'll check the colours and if they match just go ahead. Otherwise, my next task will be working out how to flush the system!

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Bottom hose off radiator is a good start

there is a drain on the bottom steel coolant pipe 13mm spanner needed

Yes of course And some sort of manual. Thanks Larry365

The pink stuff is the recommended a/f!

Or you can use prestone antifreeze which mixes with any colour antifreeze

Important is to be OAT(organic) cos you can find pink HOAT too and unless you put only that in it which would be good it's not recommended to be mixed with OAT... i'd drain and replace the whole coolant with the proper stuff...never use less than 50% antifreeze in the coolant, better more than less, people used to thing that if it's summer more water can be added cos it doesnt freeze but interestingly(it's pure science though) if you fill the system with pure water it will run hotter than on proper mixage or even pure antifreeze due to the fluid's density

johnlad said:

Or you can use prestone antifreeze which mixes with any colour antifreeze

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now that sounds nice and easy

DiscoPixie said:

now that sounds nice and easy

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The question is, what colour is your existing coolant? That will state its recommended life for the antifreeze, blue 2years, green yellow (Rover's stuff) 2years or pink/red which is OAT that's 5years, so is your antfreeze do for a change?
But for me and as recommend above I'd drain, flush and refill with the correct stuff OAT and forget for the next 5years. Brilliant

discool said:

The question is, what colour is your existing coolant? That will state its recommended life for the antifreeze, blue 2years, green yellow (Rover's stuff) 2years or pink/red which is OAT that's 5years, so is your antfreeze do for a change?
But for me and as recommend above I'd drain, flush and refill with the correct stuff OAT and forget for the next 5years. Brilliant

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I need to check the colour - but no idea how long since it was changed. Better get the hose out I guess! Or else take Johnlad's advice add prestone to the current fluid.....

DiscoPixie said:

I need to check the colour - but no idea how long since it was changed. Better get the hose out I guess! Or else take Johnlad's advice add prestone to the current fluid.....

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And if you see that it's the right colour are you sure it's the right concentration too? ...better folow discool's advice... or mine before that ... but if you insist to go cheap on this and it's pink better top up with pure OAT than with an already mixed coolant like prestone

Prestone is not a ready mixed coolant it is a concentrate made to mix with all brands and all colours/type

Depends what you are googling http://www.gsfcarparts.com/976aa0421 but as you say there is concentrated version too though in this area better not rely on sellers advertising IMO before you make some research e.g the prestone has no converter in it ( https://www.lakeland.edu/PDFs/MSDS/18/Antifreeze (All Brands).pdf ) , it's like an engine oil without additives while the recommended Texaco Havoline extended life has up to 4% converter(potassium 2-ethylhexanolate) https://www.conncoll.edu/media/website-media/offices/ehs/envhealthdocs/Antifreeze.pdf ...maybe not very relevant but a fact is that prestone is NOT OAT antifreeze, its a universal antifreeze which can be mixed with both OAT and IAT while the OAT can't be mixed with IAT so IMO even if prestone might not be harmfull for the Td5 cooling system it's deffinitely not the best and it's not extended life either ... i'd not put that in my beloved Td5 myself

discool said:

The question is, what colour is your existing coolant? ...

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Rust colour?

Right, lots of advice thank you! As this is my 'beloved Disco' I want to do it right, so drain and use OAT it is. Can anyone point me to an online manual on doing this - I don't know if anyone picked up on my introductory thread - I'm new to maintaining my big orange Disco but am very keen to get stuck in myself as much as poss

download RAVE from here https://www.dropbox.com/home/Rave (Discovery II _ Freelander '01)
important is that when you fill the system to raise the tank above the bleed hole, fill untill it flows there, hook the tank up, refit partially the bleed screw, start the engine and keep it revved above 1500rpm as the mechanical bypass valve of the thermostat to be opened untill no bubbles are showing near the bleed screw, then tighten it, put the tank back, top it to limit and tighten the cap well, this way it's certain that no air is left inside.

sierrafery said:

download RAVE from here https://www.dropbox.com/home/Rave (Discovery II _ Freelander '01)
important is that when you fill the system to raise the tank above the bleed hole, fill untill it flows there, hook the tank up, refit partially the bleed screw, start the engine and keep it revved above 1500rpm as the mechanical bypass valve of the thermostat to be opened untill no bubbles are showing near the bleed screw, then tighten it, put the tank back, top it to limit and tighten the cap well, this way it's certain that no air is left inside.

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Thanks very much.

Use genuine OAT coolant, it lasts for a couple of years and if you have any aluminium in your engine you'll appreciate how it keeps the cooling system clean and shiny.

I've use genuine LR coolant in our V8 since we did the engine rebuild and it really does keep the cooling internals clean.

Peter