I have a duo air that is acting up. It was attached to a seaquest bc and seems to have been modified to do so. I don't think the modification has anything to do with the problem. It is vibrating while trying to breathe from it. If you push in on the purge ever so lightly it works ok. Does it just need to be serviced and can any one tell me how to remove the face plate to check the diapham. Thanks in advance.
Tim
Tim