Can't Drive The Mustang

[Unit 5302]

Off hand I'd have to say it's the one that is drooping down with the rim resting on the sidewall. I could be wrong, but it's an educated guess that's the tire that's flat.

Pull the wheel and tire. Pump it up to 40psi, or the maxium allowed pressure, then take a bucket of soapy water and run it over the tread. Where it blows bubbles you have a leak. If it doesn't, lay the rim on it's side and run soapy water around the beads on both sides.

Somewhere it'll be blowing bubbles. If not, and it's an intermittent flat, your bead needs to be cleaned and your tire should be checked for bead damage.