Audio Technica AT 666 is loosing air

My Audio Technica AT 666 is loosing air and want to see if any else has had this problem. if so how did you get yours fixed?
Dear Rugyboogie: It could help you if you wash with water and a neutral-soft soap, specially the rubber rings, then dry with a cotton clothe and finally you take a tape ( scotch one ) all over the rubber rings to take out the debris that leave the cotton clothe.

I think this can help you to restore as original.

Regards and enjoy the music.
Hi Rugyboogie,

Try a rubber rejuvinator on the seals. The will stop you loss of air.
Dear Rugyboogie: Agree, the Etbaby advise works too.

Regards and enjoy the music.

I have done the cleaning but she still looses air. I will try to find a rubber conditioner. In the mean time I will do a soap test to see where its leaking from.

Thanks Raul and Etbaby.
Dear Rugyboogie: Please check that on the outside rubber ring it is still all around ( outside the ruber ring ) a nylon thread, if it is good but if loose it then you have to replace because with out it does not works.

Regards and enjoy the music.
The guilty part is the air intake valve. It holds the vacuum for about 30 seconds and then releases allowing air the get in.
Is the inside valve/diaphragm easy to fix, want to know before I start taking it apart.
Thanks again
Hi. Same issue with loosing air. Did you solve it?
No did not, decided to put it away to solve another day.
It's been in my heated attic for a bit as the last post was 08.
Time flies.
Hi Rugyboogie, I also have an AT 666 that won't hold vacuum. Some time ago Raul suggested a new securement line around the perimeter but I have too many other projects ahead of this one.

If your test identified the air intake valve, can that be disassembled and repaired or replaced with help from a tire or bicycle shop?
Yes, guilty part is little rubber valve-in. I found no solution to replace it. There are special form rubber T insert. It's looks good, but not hold vacuum.
Only solution to close valve with rubber cup. Or DIY valve.
My skill not so high.