So drilled out a broken off timing cover bolt and went too far. now coolant leaks out around the bolt so I assume I penetrated thru to the water gallery where the water pump bolts on,on the right side.am I stuck cramming j .b.weld in the hole or is there a better solution?this is a 1997 GMC Sierra with a 5.7 vortec

 

If it’s only leaking from around the threads of the bolt, you should be able to seal it with blue or Orange threadlock.

Drain the block below the level of the bolt and make sure the threads on the bolt and block are as clean as possible.

Apply enough thread locker to coat 3-5 threads starting at about the 3rd thread from the end of the bolt. Torque to spec and allow to set at least an hour prior to filling with coolant and running the engine.