tire pressure loss
 

I have a 1992 Accord ex that is loosing pressure in one of the tires.
I fill the tire to 28psi the next day I'm down to 24psi, next day 22psi
this continues until about 18psi and then the pressure loss seems to
stop.The tire has been removed and the mechanic says it's ok.
I have noticed there is a lot of corrosion around the rim of the wheel
next to the tire. Could this be the cause of the problem? If so, what
should I do?