I have never had an ast on my car or coolent overflow tank since i bought it.... Unfortunatly with the warm weather im worried about loosing coolent so i bought a coolent overflow tank to install in the car... only problem is I have no clue where to run the overflow hose to... I looked through the manual and to me it looks like the line is supposted to go to the ast.... What if i have no ast? :P where does my line go?

 

Think there is one on top of the t-stat housing as well. Would have to go look to be sure though. Someone will answer before I have a chance though I'm sure.

 

Is there a nipple coming off the place where you are adding coolant to the engine? This nipple needs to be located ABOVE the level that the pressure cap's sealing gasket sits (i.e. the bottom of the cap). If your filler neck (to the left of the alternator) has a nipple right under the cap, then you've had the AST removal done. This is fine (although I prefer the AST, and so apparently does Saleen. See this month's Road & Track), and you can run the tube from this nipple that is right under the filler cap to the overflow tank. MAKE SURE THE CAP YOU USE IS A PRESSURE CAP if this is the case.

The nipple that sits about three inches down from the filler cap on the front face of the thermostat housing is the return line FROM the AST if you had one. The send is from the small nipple on the radiator. DON'T run the overflow line to the nipple on the face of the thermostat housing. All your coolant will come out!!

 

ehh i just looked and their are no nipples anywhere?? i guess I will just go and buy a cap with a nipple built into it... what pound cap do i need?

 

oh and the ast... i would prefer that i had one but it wasnet on the car when i bought it

 

I bet whomever had it before blocked off the nipple on the face of the thermostat housing. Ouch.

If you want the AST, you will need to get a new thermostat housing. Second, there are no "caps with a nipple in it", rather, it is the mount that the cap sits on that has the nipple to allow an overflow to be hooked up. Where did you get this car from? Anyway, search for "AST eliminate" and/or elimination, and there should be a thread that shows what the filler cap mount should look like if you just want to put on the overflow with no AST.

For the AST routing, try looking at this page:

http://www.autosportracetech.com/RX-7/coolingsystem.htm

In the diagram, you see the portion that has the radiator? Just above and to the right is the AST, the funny L shaped doo-hickey with three hoses connected to it. The bottom hose connects to the radiator, on a small nipple to the left of the main rad hose as you look down on the mess from the front of the car. The hose pointing off the left side of the AST leads to the front of the T-stat housing, but in your car might be missing/plugged. The third hose coming off the top of the AST is the line that goes to the oveflow.

You can get an aftermarket ASt form Pettit or the RX7store and others.

The stock system runs at 13 psi.

Hope this helps...