Tires produce leaks all the time. Road hazards such as nails puncture the tread or sidewalls of the tire, creating a noticeable leak. Cold weather causes a weak bead seal to begin to leak air. A weak bead typically causes your tire to lose from 0.454 to 4.54 Kilogram of air pressure every day. Driving and cold weather increases this rate of air loss. Repairing the tire requires locating the source of the leak and then applying a bead sealant available at any auto parts retailer to correct the leak.
Raise the vehicle with a jack and remove the lug nuts using a lug wrench. Set the lug nuts to the side.
Inflate your tire to 25 psi. Lay the tire on its side and spray the bead with window cleaner so that the window cleaner puddles up around the lip of the rim. Monitor the puddle and watch for air bubbles. Mark the location of any air bubbles with a crayon on the tire with an arrow pointing at where the bead is leaking.
Flip the tire over and repeat Step 2. Raise the tire pressure to 45 psi and repeat Step 2 for both sides of the tire.
Deflate the tire by removing the valve core from the valve stem using a valve core removal tool.
Break the bead loose by placing a pry bar between the bead and the lip of the rim. Apply ample downward pressure while the tire is lying flat on the ground. You do not need to remove the whole bead; just enough to access the bead in the section of the tire that you marked. Expose approximately six inches of bead.
Apply a generous amount of bead seal directly to the bead, using the included brush. Bead seal is a bonding adhesive that will create a tight bond with the rim when the tire is inflated.
Inflate the tire to factory specifications for your vehicle and reinstall the valve core using the removal tool. Test the tire as you did in Steps 2 and 3, except at the recommended pressure instead of 25 or 45 psi. Reinstall the tire on the vehicle and replace the lug nuts. Tighten the lug nuts and lower the vehicle. Tighten the lug nuts again using the lug wrench.
Bead leaks do not necessarily indicate a weakness in the tire or the rim. Air molecules are small enough to find a way to leak out of the tire. The fact that your tire loses air pressure is normal, unless you have to fill it up several times a month, in which case you should check for leaks.