When we do a car service we test the coolant with a Ph strip and we sometimes find that the coolant is old and discoloured. Radiator coolant usually lasts for between 60,000 kms and 100,000 kms. The old coolant needs to be flushed out and replaced with quality coolant.
Its purpose is to:
It is almost as important as engine oil and it should be changed before it stops doing its job.