Guys, thanks for your advice and the ecopy of the maintenance manual Stuart. When I took the thermostat cover off, I discovered a big piece of melted plastic stuck in the thermostat spring - not good. Worse, someone had already tried taking the thermostat cover off before me and twisted off one of the bolt heads. Drilling out the stud, upside down and on a angle with a hand drill was next to impossible so I removed the water pump. An adventure to say the least because I did it without removing the alternator. It is not my Iltis so I didn't want more things twisting off and breaking......
I purchased a new water pump and a new thermostat, installed the water pump and installed the thermostat and cover. Unfortunately, the old thermostat cover doesn't exactly fit over the new water pump opening for the new thermostat and it leaks at the edge after I filled it.
I am going to replace the tapered rubber gasket that fits over the thermostat cover with the supplied o ring, I will make a new gasket that is slightly bigger than the outer dimensions of the cover and I will use gasket goop between the metal pump housing and the hand made gasket. Correct me if I am wrong, but I hope this will provide sufficient "gap" stoppage to prevent leaking while under operating conditions. Suggestions Welcome!
Regards, Richard