Coolant for life?

From what I understand, it’s normally recommended to change coolant every 2-3 years. I’ve stumbled across this “Putoline Ultracool 12” which claims:

The use of powerful corrosion inhibitors means Ultracool 12 is practically unaffected by ageing and can be used for the entire service life of the engine.

Doesn’t the coolant normally pick up some small debris over time, which would still affect cooling? So, even the properties of the coolant itself are largely unaffected, you would still need to flush eventually to get rid of the foreign rubbish in the system.

Most coolant is water based, but there are none water based coolants out there. There was a Wheeler Dealer episode about a TR6, and Ed China completely replaced the coolant with a none water based coolant, and that would last the life of the engine.

I understand that you change coolant because it loses its rust inhibition over time.

Which if water based is an issue. If it is entirely synthetic with no water shouldn’t be issue.

I use


In all my vehicles. The 250 has a 3L coolant capacity so 2L of concentrated coolant and 5L of de-ionised water is enough to flush the system with 3.5L of de-ionised water and make up 3L of 50:50 coolant mix to refill the system. That’s good down to -36°C for 5 years but I change it a little sooner than that to coincide with a major 32,000 mile service that involves spark plugs replacement and a valve clearance check. That way everything is already out of the way and the coolant flush and change can be done in 20 minutes.

Changing the coolant gives you the opportunity to properly check the condition of the radiator hosesand if you check the condition of the coolant coming out it’ll give you an idea of the condition of the cylinder water jacket, radiator, waterways etc.

£20 every 32,000 miles for a coolant change, flush and system inspection vs £30 for a one off coolant change which may or may not last the lifetime of the engine is a no brainer for me.


I’m cool for life!

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Evans waterless coolant is what I use in the Tiger
seems to keep the temps on the bike more stable.

How It Works | Evans Waterless Coolant (

This bloke doesn’t like Evans.

Well, that’s one mystery solved :+1:

Alright, the coolant is sorted now, thanks for the suggestions.

Ehm, there is now only a small issue of radiator leak that I didn’t notice until after completely flushing the system and filling up with brand new coolant :man_facepalming: So, new rad ordered. Is there any problem reusing the 1 day old coolant that’s already in the system for the new radiator (i.e. drain the coolant into a clean container from old rad, install new rad, fill it up with coolant from container)?

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Reusing old coolant is perfectly acceptable and good practice so long as it still meets specification, at one day old it will. I use a similar tool to this to test coolant

£9 off the shelf at Halfrauds vs about £6 delivered from fleabay or Amazonia.

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Of interest and if you’re buying tools online a brake fluid tester pens can also be useful addition to the tool box. I use one similar to this

As above £30 off the shelf at Halfords vs a blue go go juice voucher delivered to your door from fleabay or Amazonia

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Thanks @National_Treasure. I change brake fluid often enough, so not sure I would get a lot of use from a tester. But the coolant one could come in handy.

My idea is to only change the brake fluid when needed, if it ain’t broke…

Now it only gets changed when it reaches the 2% indicator, which has been as short as 18 months and as long as 5 years. Don’t just measure it at the reservoir, bleed a little out at the caliper when changing pads and test it for moisture there too. I keep a small jar of the left over brake fluid for just that, just make sure it has a good seal and there is little to no air gap between the fluid and the lid and it’ll be OK.

On the other hand if you’re having to buy brake fluid to top up the bleed off you may as well buy 1L and replace it, its less than a tenner at Euro Car Parts but an extra tenner in my pensioners wallet is half a tank of go go juice down at Asda.


That makes sense. Also, likely to be more reliable than my “this brake fluid looking a bit dark” analysis :sweat_smile: