If the line has "leaks" how would they manifest themselves? Would it be possible to recharge the connection so it is at the level it should be for a full day and then go back to where it was? What do these symptoms mean?
One thing I have discovered about a lot of repair people is that they learn to do a lot of things by rote rather than by logic. Many times I have seen them make "repairs" that didn't address the problem as represented by the symptoms. My brother, who was an excellent mechanic, told me that when he wants to fix something he imagines himself to be the part, and asks himself why he would do what that part is doing. Makes sense to me, but I don't think repair people learn how to work things out this way. That is, a lot of people get into repair work who aren't particularly gifted at it.