Overheating Mirage

[Sulley]

Ok so I found this product that I think may be a solution.

http://www.jegs.com/i/Aerospace/026/...4OUxoChLDw_wcB

What if I installed this product with an overflow tank. That would give me the expansion that I need plus help eliminate trapped air in the system.

Q - if I install this do I need to do anything to my existing radiator? It has a cap and an overflow line. Does the radiator need to change to a completely closed system? Do I need to plug off the overflow line?

Thanks in advance and hopefully this will serve as a record for others.

[Blueovalz]

That is similar to what I'm using only in that I have two radiator caps on my car. I use a higher spring pressure on the front (at the radiator) that will not release pressure before the rear one (at the highest point just behind the engine) would. I've inserted a NPT plug in the front radiator fitting, but that isn't necessary if you use a stronger spring on the front cap. This is because the lower spring-pressured cap at the engine (the Jeg's piece) would be doing all the releasing and redrawing of water into a reservoir. With the Jegs part you've linked, my guess is that on warm-up, air will be pushed out (through the hose barb fitting) into a reservoir due to the cap action, and then liquid water drawn back in upon cool-down. It may take a few cycles to get all the air out (and you'll need to ensure the reservoir stays about 1/2 full -at cold- throughout the entire process). With a front radiator cap, you could crack the radiator cap to release any pocket of air in the radiator, and then seal it back down to let the rear cap to its work.