Cooling system holds it (13 psi) and doesn’t leak or drop.

But isn’t getting too much of it warm and running. (11.5 psi) without pulsing.

Pressure caps both failed. The old one because it didn’t pop off, the new one didn’t fit in the tester...hmm.

Got a new cap today and will be testing that. barring that the ONLY thing it could be is the radiator. So...Rock Auto will allow me to return this, but only for a direct replacement under warranty. If it was you, would you pay the $40 to ship it and hope the next one doesn’t suck, or drop $150 on a local one I can return directly if I have a problem?