load/suspension problem

So my left rear tire looks flat. I checked the pressure and it was at 12 psi. i filled the tire with air and did nothing. so i replaced the tire with the full size spare and my tire was perfectly fine. After putting on the spare, it too looks flat just like the original one did. Looks kinda deflated on the bottom so i'm guessing i have a shock that is out or needs to be recharged or something? If i need to replace something, what do i need and where is a good website who can order directly from an OEM manufacturing plant? I have a 98 LT with the premium ride suspension equipped. Thanks pros!

So i believe i do need new rear shocks. Just wondering if there is a special/specific one for the touring suspension (what i actually have according to original invoice, sorry.)?

Take a closer look at the rear leafs. You may have a broken leaf and its causing a sag on one side. Its really not that easy to see visually(unless its real bad), but if its sagging it sounds like a rear leaf could be broken.

a bad shock will not change the load on your tires or suspension at rest, all they do is take the "shock" out of sudden changes in suspension loading caused by driving over uneven surfaces. at rest they have no effect on the suspension or tire load.

these kind of problems are hard to diagnose by eyeballing it so get a tape measure and check the distance from ground at a variety of reference points starting with the wheel rims on each side then the high point of the the wheel cut out on the body and compare them side to side on the vehicle.

okay, i will do that tomorrow afternoon and post results.

I measured from the ground to the top of the fender/wheel well and it was off by only 2 cm. I added air to the spare (tire on vehicle) and was able to bring pressure to 30 psi so it's merely a tire issue and not suspension. Thank you all for your assistance. Been a very very solid blazer so far.