First welcome to the forum, to answer your question requires me to ask a question. Is the Bounder a diesel unit? If it is, and if the chassis is a freightliner chassis, it came from the factory with air bags and the only thing you need to do is fire it up and make sure the suspension valve is set on the "Auto" setting (not the dump) and once air pressure builds up your air bags (both front and rear) will raise. If the unit isn't diesel, then as 3wheeljunkie
stated they were an add-on and you need to do as he explained.
We bought ours four years ago and have been very happy with it, good luck on your RV journey.
Tom and Barb
2000 Bounder 39Z