I did headgasket replacement, and took it to a shop for timing and coolant flush, and they told me the coolant pressure in block is low. It holds coolant so no leaks, had brand new radiator cap, and brand new water pump. They had said its either water pump or i maybe got the gaskets on upside down? I gambled on the pump and lost. Could it be the gaskets on wrong that makes the pressure low? They had said the pump was getting coolant but wasnt getting it anywhere.