I am doing the waterpump today and finish tommorrow-- I can not get the radiator cap off at the top radiator coolant contanter the black one????? Is that supposed to stay on?? seems wierd and I do not want to break it- so far all hoses are off and coolant drained and 1 bolt out on pump--- 5 more to go no more time today please help thank you...

This cap can be a real PITA to remove. Make sure you support the bottom of the reservoir so you don't break anything, then you will need to really push down on the cap to get the tabs to disengage from the neck of the reservoir. It does come off but old caps are difficult to remove.

Before you try to remove it again, take a good look at the cap and how it engages with the neck of the coolant reservoir. You should notice some notches that the cap locks into. You will need to puch it down enough to clear those notches or tabs (whatever you want to call them)

If you get it off replace it with a "safety release" cap

They're a lot easier to use