Hey all, I'm in the process of changing the coolant in an 05 XRJ and need to know what size hex tool to use to get the supercharger coolant fill plug open.

I've searched the forums and there is a post that says either a 15mm or a 9/16 will do. However, I purchased a hex tool kit with a 9/16 (that is all they had) it is way to small. I pulled out the next size up a 5/8s and it is still too small. Does anyone know what size it is? Thanks in advance!

My 06 XKR uses a 19 mm hex.

19mm Hex Socket, 1/2" drive should do it. See below:

A small spark plug socket also has a 19mm hex, just use it backwards

PS there is no need to remove the plug
Jut raise the front end and fill from the reservoir
I just put mine on car rams which is perfect

Remember never run the engine with the cap off
Just fill and let the two coolant pumps do the work for 15 mins or so, then run up to temp and let it cool. Once coll top off the reservoir

Cheers
34by151