2000 air suspension problem

i noticed in the past week my air suspension pump has been running on and off a lot when the car is off and on level ground. this morning i notices the rear of my truck is sitting low. i drove it to work and it was a rough ride bouncing around and shaking the steering a little.
im new to air suspension...where do i start?

after doing some research on here and all over the web....im opting to put on a conversion kit and ditching the air ride all together. strutmasters.com and arnottindustries.com have decent deals. im going to replace the rear only for now and go from there....hopefully this will work. ill post my results and what i paid etc....

i think Advance Auto Parts offers a kit to that may be a few dollars cheaper

well i doubt it. i order these from strutmasters on ebay for 137 bucks for the pair. its an open box sale. has all the parts and full warranty and installation instructions etc. they have a bunch more. this is just for the rear kit doesnt come with shocks. i would take one of these kits over the one at advance anyways...its made in usa and powder coated and the warranty and overall quality is better. i try to avoid "made in china cheap" at all costs

just realized the advance kit is from monroe shocks and come with shocks...thats actually looks like a decent kit and i believe monroe is still made in usa

i have monroe lt shocks on my 01 exped and they do a very good job