The recovery tank cannot be air tight. If it was then when the vehicle is running the recovery tank would be pressurized just like the radiator and that's a bad thing, especially since you are using a glass container!
It sounds like it is set up correctly. The tube that goes to the radiator goes thru the recovery tank lid down to the bottom of the recovery tank. The other opening in the cap serves as a vent. The radiator pukes fluid into the recovery tank and then when the engine is off and the radiator starts to cool down the vacuum that results from the cooling will suck the fluid, via the submerged tube, back out of the recovery tank.
It's no different than drinking Coca-Cola from a straw. As long as the straw is submerged in the Coca-Cola you can suck the Coca-Cola out of the bottle. If you somehow had the straw in the bottle and the pop bottle was sealed you couldn't suck the Coca-Cola out 'cause you would be inducing a vacuum into the bottle.
Last edited by Hot Rod John; 07/02/2011 3:42 PM.
