Devin,

Jon already mentioned the aux pressure and it being adjustable. If you think the leak is the floor slide, just put it in the out position and with the door open, you can get to the air cylinder and squirt it with some soapy water. It sounds to me like you have more going on than the floor slide or else your aux compressor has a serious leak. Keep looking, you will narrow down the leaks, but you'll never be leak free!

Here's a few general places to look for aux leaks with your vintage:

Steering bay
Floor slide
Generator bellows & regulator
Grey water by-pass cylinder
Waste tank dump cylinder
Air horns
Toilet - if it's air like mine
Aux compressor & fittings