Suspension air bag repairable?

Last week my son bought his first car - a 1994 Continental. He's very proud of it, like we all were with our first cars, but it comes with a problem which seems to be common with these cars - a leaking rear suspension. The air bar seems to pump up OK, but when the car sits for a while the rear end bottoms out. After doing a bit of research online I think he probably has a leak in the air bag. My question is, do they make air bag repair kits, maybe something with a patch and some kind of silicone sealant?

You'll have to replace the airbag spring. I've used Arnott Industries -
http://www.arnottindustries.com/ provides aftermarket air suspension components for your car and other makes with air suspension. Their prices are good and they provide fast service

Don't forget the life time warranty!
If the rubber isn't old, find the leak with soapy water, and try a patch with super glue.
If it's the original, buy new & be done with it.