1. Add some RMI-25 to my current old coolant and old thermostat.
2. Run for a week to restore metal surfaces to normal, protect the metals and suspend any contaminants.
3. Then drain and fill with distilled water/White Distilled vinegar at 50/50, Run engine until warm
4. Let cool
5. Drain
6. Run distilled water through to rinse out vinegar, twice!
7. Fill with coolant, premixed (EG) Ethylene-glycol 50/50 or concentrated (EG) Ethylene-glycol with 50/50 distilled water/Deionized water.