hey all

so my radiator recently went on my FD , and so i ordered a CX racing one question i have is on the old rad there are 3 hoses going into it a top and bottom coolant hose and another that i think is an air seperation hose , on the new rad it does not have aport for the air seperator , do i need to keep this on or is there some way i can plug it , everything else in the engine is stock .

any help would be great , thanks !
scott-

 

The smaller bottom hose is for the AST. It plugs into the bottom of the AST. I have a Fluidyne radiator and it came with the hose port. I would think that blocking the bottom port of the AST would defeat the purpose of the AST. I have seen threads on AST elimination but I have also read this could be a problem. I would recommend taking it to a radiator of fabrication shop and have a nipple welded on to the lower tank. It probably wouldn’t cost much and would allow you to maintain your AST setup.

 

There is a way to remove the AST from the system you would need to buy a few parts.
https://www.rx7club.com/showthread.p...ht=ast+removal

 

hey

thanks for the help guys , i was just wondering what AST stands for and i noticed that the easiest way was to run the hose line from the bottom up to the top of the thermostat . is it that simple ? lol

thanks again

 

AST air separation tank. Read the thread on AST elimination it will explain how to remove it. You can’t run the hose directly to the thermostat housing because the cap is not a pressure releasing cap.

 

You can get the FC coolant filler neck for the AST elimination from Ray at Malloy Mazda for like $40. The number is (703) 490-8263 if you're interested. My brother hooked mine up and so far so good. I bought a coolant specific funnel at NAPA for less than $30 that holds coolant in the funnel so it automatically fills as the air escapes. If you decide to eliminate the AST I would use this method to do your best to ensure "all" the air is removed from the system.

 

ok thanks guys !

 

hey all !

spent this afternoon putting the new radiator in , had to make a lot of cuts from all the plastic stock parts to make it fit . but everything went back together and is working better then every , idle is even smoother . I ended up just plugging the line at the bottom of the AST and she seems ot be holding up good

thanks for the help again !