Anyone else having this problem?
Well I was installing mine, with all the hose attached. So I lean it aside to get some other tools, it started dripping fluid from the cap area. Seems like the cap isn't clamping down all the way or it's defected.

I checked again reseating the cap and closing the clamp. Tilted it upside down, and once again fluid was able to seep through.

What's wrong? Do I need a new cap, or was mine machined not to the exact measurement for the cap that was sent?

 

Make sure the nipple on the top has thread tape and is tight,other than that the only possible thing it could be is the cap is faulty,everyone of the tops are cnc machined and will neverleak So go to the local parts store and ask for the radiator cap for a 57 chevy (16lbs)and try that, this will solve your problem.I f not call us,not the RX7store,and Ill send you out another one that day!