So I was digging around my 06 LSJ a couple weeks ago and noticed that my overflow/return line (the smaller one on the top left front) out of my coolant system surge tank (not my option b) was plugged with an AN fitting and a worm gear clamp. I figured this wasn't right so I took it out thinking it was just for overflow to atmosphere. Well, now I can't build pressure in the system and I am adding coolant all the time. I am guessing as the car warms up it is just all overflowing out of the tank due to the pressure increase.

So the question is, were does this line normally come from, and I guess maybe more importantly, is there any reason they would need to bypass and clamp this line. I bought the car back in 2012 and it has had a lot of "hack" repairs done that I have seen. So I am wondering if they weren't using this to cover up an existing problem when I bought the car or if they just skimped on a repair. Also, there is not a tube at the mouth of this tank like the option b has.

Thanks in advance, if ya'll need any further information please let me know.

 

Alright, so digging around I finally found some decent engine bay pictures without the covers. I am completely missing the metal tube that goes from the top radiator hose engine entrance. There is a square head bolt in its place. I should be able to just get a npt to barb and run it that way correct?