Draining your car's coolant is a straightforward DIY task if you're comfortable with basic tools and safety precautions. The core process involves safely removing the old coolant from the radiator and, optionally, the engine block. Always let the engine cool completely before starting, as the system is under pressure and contains scalding-hot liquid.
You'll need a few basic items: a socket set or screwdriver for the drain plug, a large pan to catch the old coolant (at least 2-gallon capacity), safety gloves, and goggles. Coolant (a mixture of antifreeze and water) is toxic, so you must handle and dispose of it responsibly. Never pour it down a drain; take it to an auto parts store or recycling center.
Here’s the basic procedure:
- Cool Down & Locate: Ensure the engine is cold. Park on a level surface and set the parking brake. Open the hood and locate the radiator. The drain plug is typically a plastic valve or petcock at the bottom of the radiator.
- Place Pan & Drain: Position your drain pan directly under the plug. Carefully open the radiator cap (if the engine is cool) to break the vacuum. Then, open the drain plug and allow the coolant to flow out completely.
- Flush (Optional): For a more thorough job, you can flush the system with distilled water to remove old residue. Close the drain plug, fill the radiator with water, run the engine until the thermostat opens, then drain again. Repeat until the water runs clear.
- Refill & Bleed: Close the drain plug securely. Refill the system with a 50/50 mix of new antifreeze and distilled water. Start the engine with the radiator cap off and let it reach operating temperature, allowing air bubbles to escape. Top off the coolant level as needed.
The frequency for changing coolant varies by vehicle. Check your owner's manual for the specific interval, which is typically anywhere from 30,000 to 100,000 miles.
| Vehicle Age / Type | Typical Coolant Change Interval | Key Consideration |
|---|
| Modern Cars (Post-2010) | 60,000 - 100,000 miles | Often use Long-Life coolant (HOAT/FOAT). |
| Older Cars (Pre-2010) | 30,000 - 60,000 miles | Typically use conventional green coolant (IAT). |
| High-Mileage Vehicles | 30,000 miles or 2 years | More frequent changes help prevent corrosion. |
| Heavy-Duty Use (Towing) | More frequent than standard interval | Extra strain demands better system protection. |
| Electric Vehicles (EVs) | Up to 150,000 miles (varies greatly) | Cools the battery and power electronics. |
