coolant leak need help identifing

[KJ2000XLS]

thanks for the update. i have my caliper in hand heading out door this morning. going to try a couple of things. big but thin adjustable ? big but thin vise grips ( pretty sure thats not an option on the thin part ) , big channel locks ?, or the true 36mm wrench. hoping harbor freight or northern will have what i am looking for at a reasonable price. also saw a post about someone using a long handled 10mm wrench and wedging it to hold assembly still.