Coolant requires periodic replacement to prevent contaminants causing damage to cooling system components. This can be every other year with conventional coolant or every 5 years with extended life coolant. The goal is to get out as much old coolant as possible and replace with fresh coolant.
This service is especially important as part of winterizing your car. We can test your coolant to make sure the freeze point is not higher than it needs to be, because with extended use the temperature resistance of your coolant can slowly degrade over time.