The normal direction of circulation in the coolant system would push the coolant out the thermostat opening.
I don't know the reaction it would have on the coolant but I would advise you to flush out your system immediately and put in fresh coolant.
Coolant leaking inside would smell sweet, so either you have a piece of plastic melting on the element or your fan motor is starting to short out.
In systems that do not have a radiator cap, the coolant is drained by the radiator drain plug. It is filled by adding coolant to the system through the overflow bottle.
I would but there is no way that I can do a diagram
A diagram of what? The electrical system, vacuum circuits, it would be good to know what you are referring.
what is the question? why it would overheat???? if so: because -thermostat is stuck closed -or no coolant -or head gasket leak -or coolant system leak -or bad water pump -or clog in coolant system -or ......
There are sites which sell all different types of automobiles in operation, and example would be autotrader. However, the Vanagon actually has it's own website dedicated to it, simply named vanagon. On this site there are links to other pages where people have them for sale.
I would have the cooling system flushed and coolant replaced. DEF is very caustic.
You would have a leak in the coolant system somewhere and you need to have the system pressure checked.............
Yes it can. A faulty thermostat can cause overheating which will cause coolant to be pushed out of the system.
Yes. It doubles as an expansion tank for the coolant. Without it the system would be total loss and you really don;t want to run out of coolant on that engine.