How often should Evans Waterless Coolant be replaced?

[McRichard]

Determining whether coolant has deteriorated is not simply a matter of observing color changes with the naked eye or estimating based on time. The correct method requires professional instrument measurement, which is generally available at authorized 4S shops or auto repair shops. Below are the relevant steps: Check for leaks: Open the cooled engine cover and first inspect the cooling system pipelines, joints, etc., for any signs of leakage, and clean the relevant parts. Drain and clean: Drain the existing water or water-based coolant from the radiator into a shallow basin or bucket, observing whether it is clear, transparent, and free of impurities. If it is generally acceptable, rinse the cooling system twice with clean water.