PlEaSe HelP!!

***1999 Audi A4 1.8T Quattro***

what size is the banjo bolt that connect the water line/water supply line hose to the turbo, the one that has the coolant running to the turbo. I have seen everywhere that its 14mm or 17mm or 19mm... i just dont know what to believe. Also if anyone could help, what tool would you reccommend to get into that tight space? Thanks in advance for the help! Coolant is leaking out/ dripping out from that area where it connects to the turbo and i need to replace the crush washers.

if anyone has a link or could help me out with a step by step guide to replace the crush washers on the water line, then please post it, i dont want to have to take a bunch of stuff off just looking to see if anyone has had this issue !! Thanks!