Case 830 CK Heater Hose Help

[splashgtp]

I have a 1968 Case 830 CK with diesel engine. I never tried the heater before I took the cab off. I just put it back on and I can't get coolant to flow. I don't know if the lines are hooked up right. The hoses and heater core are not plugged.

-1 heater is hooked up to the water pump.

-the other hose is hooked up by the thermostat

While the tractor was running, I took the hoses off but there is no flow if they are held above the coolant level.

Thanks