An aluminum or special type wheel may be porous and leak air. Locate the leak by inflating the tire to 40 psi and submerging the tire/wheel assembly in water. Mark the leak areas. Remove the tire from the wheel and scuff the inside rim surface with 80 grit sandpaper. Apply a thick layer of adhesive sealant or equivalent to the leak area and allow to dry for approximately 6 hours.
Aluminum is very susceptible to the action of alkalies often found in various detergents and on road/sea salts. If the wheels have been exposed to these types of compounds, wash the the wheels with a special wheel cleaner or mild soap and water. Do not use harsh detergents or solvents or else the protective coating may be damaged. If steam is used to clean the vehicle, do not direct the steam at the wheels.
NOTE: When changing an aluminum or special type wheel rimmed tire, finger tighten the lug nuts first, then torque them to the proper value. DO NOT use an impact wrench to tighten the wheel nuts. DO NOT use oil on either the nut or stud threads.