So my radiator overflow tank has sprung a leak and I need to replace it. I'm thinking about replacing it for an aluminum one, but all I can find is CXRacing's universal one for the FC. I did a search on Google and here, but I can't really find anything for a FD. What options has everyone used? If there is already a thread on this that i didn't see, please post the link or send me a PM with it.

 

AFAIK no one makes a metal overflow tank specific for the FD. Replacement OEM is available.

 

Have you inspected yours? When there is a problem with the coolant system or seals the tank will overfill and spill out through the vent hole in the top of the tank.

 

Uh oh. Not good--- has your engine run hot recently?

 

Dang, is there a store to buy it from or just used parts on the board?

When I fill the overflow tank it leaks out from the very bottom. I don't see an actual hole, but it's right where it looks like it was placed together.

I don't believe so, but my motor did sound a bit weird when I turned it off. Kind of like a rotor was still spinning or something. Not sure, I haven't heard that sound before.

 

You need to be sure it's not building pressure into the cooling system from a blown seal.

 

Pull the fender liner and then the tank to examine it out of the car. Whenever someone thinks they're leaking coolant from there, it's natural to think of a coolant seal failure. I just didn't want to jump directly to the worst case scenario. Hopefully it's truly just a failed tank. They're available thru Ray Crowe, your local dealer, and I've even seen them come up new in Ebay. Kinda pricey for simple blown plastic, but there ya go.

 

It's pretty simple. A cooling seal failure will pressurize the system when HOT, and it typically blows out after shutoff. If it leaks cold it's the tank.

 

Are we definitely taking about the overflow tank and not the AST?
Either way, you're better off with a new stock unit. Call Ray, Atkins, Mazdatrix, your local dealer...
New stock stuff will last another 20yrs.

 

Thanks everyone for your advise!
It leaks when the car is off from under the tank itself, so I don't think it's a seal issue. Unless I'm missing something other test I should check? The motor was rebuilt a little over a year ago and it hasn't seen much driving since.
For Ray Crowe, is this the correct number in the thread?
https://www.rx7club.com/power-fc-for...mazda-1033616/

 

Yes, at the very end (email is there as well). Shipping is a little steep, but is worth it my book for the knowledge and response you get from Sir Ray.

 

Thanks! Just ordered one from him!