BUBBLE CREATE WHEN WATER HEAT UP, MORE BUBBLE MAKE TEMP HIGHIER, BUBBLE BLOCK METAL RELEASE HEAT INTO WATER.SO BUBBLE WILL BE REMOVED TO BUBBLE REMOVAL TANK BEFORE WATER GOING INTO THE ENGINE.100% WATER WILL COOL DOWN YOUR ENGINE PERFECTLY.BUBBLE WILL GO THROUGH BUBBLE REMOVAL TANK AND FLOW TOWARDS THE SPARE TANK.THAT'S ALL. :hmmmm2: SORRYLAH, ENGLISH NOT VERY GOOD............