If your vehicle is showing tire loses air rapidly or will not hold air at all, here are the most likely causes and the parts you'll need to fix each one.
A nail, screw, or severe road debris has punctured the tread or sidewall, or the tire has suffered a catastrophic blowout, allowing air to escape rapidly.
The rubber valve stem has dry-rotted, the internal valve core is loose, or the TPMS sensor retaining nut/seal has failed, venting air directly from the inflation point.
Heavy corrosion or rust buildup on the inside lip of the wheel rim prevents the tire bead from creating an airtight seal, causing rapid deflation.
During a recent tire mounting, the bead was not fully seated, lubricated properly, or the rim wasn't cleaned, causing the tire to immediately lose air.
A severe impact with a pothole or curb has physically bent or cracked the metal wheel, breaking the structural seal between the wheel and the tire.