Every place I've seen with the hollow bolts, there is a crush washer on each side of the banjo bolt. Copper washers seem to work best for me and they are available at nearly any auto parts store, known as "brake system washers".

(I've heard, from here on the forum, that crush washers are reusable when heated with a propane torch. I personally haven't tried this)

Double check that torque. It sounds kind of low to me. 20 Nm = 14 ft/lb

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )