My evap has been leaking in my 97 2500 for some time now and it's a pain to get to it and a couple of people suggested using the stop leak. What's the pro and con of using this stuff? Will I hurt the system with it? I never have liked using the 'bandaid' approach but it's going to be awhile before I can pull the evap out and it's getting hot here in the Houston area again... .