Cooling System Service – Recommended every 3 years or 30,000 milesService Includes: First, the entire cooling system is cleaned, then all debris and worn out coolant is completely removed from the system. Check all hoses & belts; Pressure test cooling system; Check heater, defroster & cooling fan operation; Refill antifreeze coolant; Ensure proper pH balance & maximum protection; Check for leaks. Conditioners are also included to prevent rust and corrosion and BG Universal Cooling System Sealer is also included to help prevent leaks.Why: Over time, coolant is depleted of buffering ingredients and becomes extremely corrosive, literally eating holes in cooling system components. By-products of corrosion damage, as well as rust and scale, clog the passageways that conduct the water through the radiator and choke off the flow. This may result in an overheated engine that can be damaged beyond repair. Changing antifreeze regularly helps prevent premature failure of the radiator and water pump.