I've also seen where the rad pressure cap is not on the rad but on the return to the pump.

 

I would really like to sort this out so that I get a clearer picture of the correct set-up.

 

Advice appreciated.

 

George ( down under)

The filler cap in my race car is just that. It closes a hole and seals it. I have a 1/4" ID hose from the highest part of the water pump outlet, or in one car the wirl pot, and that hose runs into the bottom of my pressure tank. That tank has the pressure cap on it. A 22 pounder.

 

The tank is started off at 1/3 full of coolant. After a few runs to temperature that tank must be topped off. As air is collected from the engine, it pops to the top of the tank. When the engine cools slightly, the volume change can pull only coolant back down the hose, but no air.

Been working since 1980.

 

Lynn E. Hanover