I am purely guessing, there is a fabric, maybe leather inside. Could this be dry? I remember siphoning 3 and 1 oil into the motor to make it work. That was 40 years ago. You manually manipulate the motor going back and forth. I think I used a rubber hose and sucked up the oil into the diaphragm. I hope someone else knows how to do it, I am sure mine is going to need repair too
