I have a 1973 Toyota Forklift with a 1.5 L (1,493 cc) 4P engine. I bought this out of a farmers barn, It ran fine when I first got it, but it would look like it would start to overheat. I changed the fluids in the engine, flushed the engine and radiator out, replaced all the water hoses to the radiator and to the converter. Now the water does not flow through the converter and it freezes up with in a few minutes. I do not see any water flow, or hot water in the radiator. The converter freezes and the engine dies before the engine gets a chance to over heat. I had a mechanic replace the thermostat, however, I do not know if it is in the correct direction. I am in the process of replacing the water pump, the original is off, it did not leak, does not look bad, the bearing grinds a little, I will replace it. I am in the process of removing the water pump housing, the channels do not look restricted, however, I do not have it all the way off yet, the bottom passenger side bolt is fused to the housing at the moment.

Questions: How to tell if the thermostat is installed correctly? Does the spring face down, into the engine, or face up into the hose?

Does anyone have any suggestions of why the water is not flowing through the converter, or the engine?