Vern it maybe easier to reseat the tube on the o'ring if the leak is from there.
It is important that the 2 (o ring and tube) have no dirt anywhere.
I usually give each a squirt with a contact cleaner then apply white petrolum grease to both surfaces, then without too much force and twisting motion allow everything to bed together, if it feels tight, you may have pinched the o-ring. If you have to replace o'rings it may be easier to take off the tappet cover, undo the rocker and using a piece of wire change the o ring. I have used this method on Harley's with great success.