There is a 555 gas tractor 60 miles south of where I live that I am strongly considering buying. I had a look at it and was hoping against hope that I would be able to see some coolant when I removed the rad cap but unfortunately this was not the case My friend has a pressure tester that I can borrow but I need to know the system pressure rating which to my understanding is usually on the rad cap. Would somebody know this pressure. I just don't want to go all the way down there and find that is has some aftermarket cap with no pressure number on the cap.
Getting ahead of myself here if the test fails and I can't see any obvious leaks how likely would it be that the head gasket or maybe one the liner o-rings has sprung a leak?