The o/flow pipe from my cold water tank drips fairly frequently(flat with g.c.h. & water tanks sited immediately above h/w immersion type cylinder). When I flush my bath/r. toilet the drip sometimes stops. I recently noticed that the back wall of the toilet bowl is often wet. If there is a faulty seal on the toilet system could this be overworking the ballcock arrangt. of the water tank & causing the drip? I have already tried bending the lever of the b/cock. It"s an old system.