Antifreeze anti corrosion properties

[daverclasper]

Hi. Can I assume that if current anti freeze in the cooling system, is clean and clear, it is doing this job, as would have some brown rust discolouration, if not? 

[johny]

Thats what I go by Dave although of course it still needs changing at the recommended intervals to keep the correct anti freeze and anti corrosion properties...

[Colin Lindsay]

Run it for a year or two with no antifreeze and it looks like this:

[Nigel Clark]

15 hours ago, daverclasper said:

Hi. Can I assume that if current anti freeze in the cooling system, is clean and clear, it is doing this job, as would have some brown rust discolouration, if not? 

If you run with antifreeze until the coolant starts to look discoloured with rust, it's been in the system too long and the inhibitors have been exhausted.

Best to change blue glycol antifreeze every two years, before it gets discoloured.

Nigel