Refill engine coolant, without trapped air. (unique method) Gen 2

It was time to do my first coolant change. I read a lot of information here,(Prius Chat) and realized that trapped air can be a real time waster to remedy. The use of an air-lift tool is the solution to a carefree job. I've never needed such tool for previous vehicles, so I was without. What to do? I was thinking about this for a couple of days, before the light bulb moment arrived. Fill the coolant from the bottom up! The air should stay on top of the new fluid, and exit out the opened radiator cap. Time to try... If successful, I would share this method...


(1) Drain all fluid out of the thermos bottle petcock, making sure to have the passenger side jacked up some, as this will allow more fluid to drain. Be patient, as it takes a while for all six quarts to empty. Now leave the petcock open.

(2) Now you will need a S hook, or something to hold a jug to the hood latch. A long piece of plastic tubing is needed. ( 7' long x 5/16"(8mm) inside diameter) Test fit the tubing to the petcock before proceeding. Warming the tubing with heat will soften the plastic, if needed to expand and fit properly.

(3) A hole needs to be made in the bottom of the jug. I used a tapered shank to make the proper diameter hole. Go a little at a time with your tool, test fitting the plastic tubing. You want a nice tight press fit.

(4) Hang the jug from the hood latch. A funnel will allow the new coolant to pour into this container. Block the end of the tubing with your thumb, and fill the jug, or hold the end higher than the funnel, then seal the end with your thumb. Now bleed all air out of the tubing before attaching to the petcock.

(5) The new coolant will fill much faster than it drained, due to the height of the jug. Do not let this jug run dry, as you will have to re-bleed the plastic tubing, to remove the air that is now in it.

(6) After six quarts have been added, you will see fluid cresting the radiator cap. Close the thermos petcock. Remove the jug and plastic tubing. Keep the passenger side jacked up slightly, from step #1.

(7) Run the thermos pump with a test meter, or paper clip, and listen. The difference in sound between air/no air in the system is huge. I did four 5 second runs. There was a little air.

(8) Shove a funnel, or something that fits tight in the radiator cap location. Squeeze the large diameter radiator hose under the radiator cap many times, and see if any air bubbles come out. When satisfied, start the engine, place car in neutral, and let the engine run for about ten minutes. Make sure to set the parking brake, along with wheel chocks. The fluid level in the funnel will rise as the fluid warms and expands. Shut off the car, and let things cool. Now remove the funnel, and attach the radiator cap. You are finished...


Note: Two days of driving and all is normal. I monitored coolant temps with Torque Pro, just to be be safe.