Radiator has a hole at the top, and the reservoir has it's own top too. You fill the radiator through it's hole, and the reservoir separate. Type of coolant depends on your region.. usually 50/50 is standard but if you live in a hot place you can use a higher mix of water to antifreeze for better cooling. In my case, I can buy oem coolant premixed from the stealership if I wanted to. See what your manual recommends, and your capacity.Well I've been working on it ,and got the housing off the block,and it's the little rubber gasket inside the housing. I ordered the gasket fom autozone for $8. It's a bear to replace but doable. Now to figure out what kind of coolant and how to refill the radiator.