I tryed looking for a air release but could not find one. Also when I go over bumps the back ends goes over to one side.
I have air ride on my park avenue and it is riding really high on the back. on 2002 Buick Park Avenue
Some basic tests and inspection would need to be done before making any sort of guess. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online
That system has a down solenoid in the pump module that gets rusty and locks up due to moisture in the system. An online company offers rebuilt or used and tested pump units (suncoreindustries.com). The pump is usually located in the right rear fender behind the tire. On my car the two white wires going to the pump module are the down solenoid. Don't test this without supporting the car because it will come down on you. GM offers new head unit for this pump for about $125.00 but you can get the whole unit used and tested for $100.00 plus shipping. Suncore sends a recharged desicant filter ($35.00), that you need, with their units. Troubleshoot first. The black wire is pump ground and the green or black and green stripe wire is pump power. Good luck.