Start over
I struggeld with the same problem and here's what I did . At this point you should abandon the "fix it" approach if pumping caulk in and try the "repair it properly" approach. I would completely remove the chainplates, clean out the areas, and reinstall with a proper bedding method/material. When you remove the plates, check for core damage at the area and address this if you find any damage repair it. Assuming the hole is dry, over drill it, fill with epoxy, and them redrill for the bolt size. This will protect the core from future water leaks. Then bed the plate with proper material, eg, 4200. Set in place, lightly tighten, and then let dry before finally tighening. Viola! Leak fixed for multiple years and no ugly caulk goop! Brad