[Lew Silverman]

Roy,

The system is designed to run "under pressure", so the first place I'd look would be at the cap to make sure it was relieving that pressure, above the PSI rating on the cap into the overflow container. If you can get a hold of a cooling system tester - Stant used to make a good one, but so does Mac, Snap-on and Cornwell, it will make the diagnostic's easier.

I run a 7 PSI cap on my 'wagon, which gives me just enough pressure to ensure proper cooling.

Good Luck!

Lew