How to Bleed Air from the Radiator?
2 Answers
To bleed air from the radiator, follow these steps: 1. Drain the old coolant and flush the liquid channels with clean water, ensuring a continuous flow through the engine cooling system; 2. Start the engine and let it idle for 3 to 5 minutes to circulate the water; 3. Continue adding clean water until the water coming out is clear. If the return hose is not blocked and water flows smoothly, manual bleeding is unnecessary. The vehicle's water reservoir has two hoses: one supplies water to the engine, and the other is a return hose connected to the radiator or cylinder head. Note: After filling with water, do not immediately tighten the reservoir cap. Start the engine and wait until water flows continuously from the return hose before tightening the cap.
I'm really into DIY car repairs and have bled the cooling system several times. The basic steps are: First, start the engine and let it warm up until the temperature gauge reaches mid-range, then park but keep it running. Locate the bleed screw under the hood (usually a small metal piece), loosen it slightly - go slow to avoid scalding. When you see bubbles hissing out, wait until only clear coolant flows without bubbles, then quickly tighten the screw and shut the engine off. Don't forget to check the overflow tank level - top up with coolant if low. The whole process requires patience for several minutes to ensure complete air removal, otherwise poor circulation may cause localized overheating damaging the water pump or engine. Last time I did it myself, saved hundreds in mechanic fees - felt quite accomplished. After finishing, take a short test drive to confirm stable temperature with no abnormalities.
