The 2F cooling system doesn’t have to be pressurized to cool. I ran my cruiser for 3 years without a pressurized cooling system.
I modified the radiator cap (with vise grips) to disable the pressure valve and check valve part of the cap so it would flow freely to and from the overflow tank.
In a pinch you can also just crack open the radiator cap so it doesn’t seal tight. It’ll overflow coolant while the coolant is heating up to operating temps but once it gets up to temp it’ll stop overflowing.
The only thing different when running an unpressurized system is to let the engine cool down at fast idle for a couple minutes prior to shutdown after running hard to prevent boiling inside the engine from heat soak. No biggie if it does anyway.
Like I said — I ran it for 3 years unpressurized. Desert in the summer too.
Most leaks won’t leak if the system isn’t under pressure.
