AntiFreeze
This is an older MCW372 block i picked up at frys
Must of been a scartch or somthing on the anodizing inside the block that made it fail
This block is less than 6 months other block looks fine exept for a bit of anodizing comming off the inlet and outlet on the inside with just a tad of corrosion
ps: I still think the quility of the swiftech stuff is second to none ..so i dont know why this did this