Radiator leak can't find
 

Looseing anti freeze but cant locate leak do not see drips anywhere.
Looses about a quarter gal. Every two to three days.
Maybe about 30 miles driving

I've moved your question from General Tech Help to S-Type forum. This is the place to post technical questions about your model.

Graham

It could be the pipe in the valley underneath the supercharger.

https://www.pistonheads.com/gassing/topic.asp?t=1585174

It seems to be a common complaint.

Pressure test cooling system (15 psi) when cold. Your leak should surface. Good luck

+1 on that.

I've found with the engine running and coolant warm, small leaks often evaporate quickly, making them difficult to identify. I've had good results with a pressure tester on a cold engine.

If you do find an external leak, be careful with the diagnosis. The fan tends to blow any coolant around and it may collect in other spots and steer you wrong. That's why I like the pressure tester, so you're not dealing with potentially misleading results from coolant being blown around by the fan.

Pay particular attention to the radiator header close to the DCCV area.