Finally found time to troubleshoot the abysmal brakes on my 87 GN and came to the conclusion that the accumulator is shot. While the accumulator is an easy part to replace I realized I can purchase an entirely new vacuum system from Kirbans for only $200 more than the accumulator costs at NAPA. The problem is I have no idea how to do the conversion. Is it a pretty straight forward job (for a novice) or is this a bring it to a real mechanic sort of thing?