Looks like it wasn’t the radiator after all (as some had thought). It was this small hose. So, I’ll be replacing it along with all the others.
And whilst I’m here, a couple of more questions.
1. What is the best way to clean the mating surfaces where the thermostat housing o-ring goes? I don’t want to damage the surfaces, and they are quite cruddy.
2. There seems to be a small amount of rust inside the coolant pipe that attaches behind the carbs (around the opening that connects to the thermostat housing). Is this something I should be concerned about?
And whilst I’m here, a couple of more questions.
1. What is the best way to clean the mating surfaces where the thermostat housing o-ring goes? I don’t want to damage the surfaces, and they are quite cruddy.
2. There seems to be a small amount of rust inside the coolant pipe that attaches behind the carbs (around the opening that connects to the thermostat housing). Is this something I should be concerned about?