I have about fifty years of hands-on experience in the maintenance of everything from sewage pumping trucks to guided missiles. History shows that the opening up of a working sealed system in the name of preventive maintenance is about as likely to do harm as good. In order to verify that all is well you run the risk of introducing foreign mater, getting the thing reassembled incorrectly, and/or, not getting it sealed back up again. Over the years, I have seen that the more inspections you do and the more maintenance on condition you do, the better off your operation will be. The only rationale behind blind, on-schedule disassembly is to establish a pre-failute scheduling scheme. Cadillac has done this and published the results in the form of a manintenace schedule in the service manuals. The dealers don't like the idea of extended maintenace scheduling because it cuts into their bottom line. The result is these cockamamey maintenance items they dream up and spew to the customers.
