A/C Vacuum Motor Repair

So 2 out of the 4 vacuum motors for my factory a/c are not holding vacuum, which is causing my woes. All my air is blowing out of my heater duct at the floor. So I have both of them off and they will not hold any vacuum what-so-ever. Is there a way to repair them and get them working again?

Thanks,
 
wow, I just found this thread using google and can't believe no one responded! I have the same problem on my 67 and so far I haven't taken a real good look at them yet. I have seen new ones at npd for about $52.(more then I want to spend) I will try to take one apart and see if its repairable.
 
Well, I took a look at one and found the source of the leak. I put some medical grade silicone on a toothpick and smeared it over the small crack on the side wall of the diaphram. It doesn't hurt to try. I'll post back with the results.
 
Success! I repaired two of my leaking vacuum motors with silicone. First I found the leak by blowing air into the motor and tipping the diaphram to find the crack with a flashlight. Secure the tipped diaphram by clamping on the bracket extended out from the diaphram. I then cleaned the area with isopropyl, scuffed the rubber with a bottle brush, smeared medical grade silicone over the crack, and sucked air through the crack to draw in the silicone and let it dry for 24 hrs. I don't know how long this fix will last, but I have put off spending $100 for a while! Grayle