I'm finally going to fix my heater. And I think I know the answer already, but:
My radiator cap opens at 7 pounds of pressure. That means that my complete cooling system, and therefore also my heater, will be under a maximum of 7 pounds per square inch, right? I want to pressure test the heater core, and I figure that if it's 7 pounds/square inch I can test it by just putting the garden hose on one side and keeping my finger on the other side.
