Dave,

When you take the wheel apart you'll notice a thin O ring in a groove that is machined into one of the wheel halves. On occasion, this O ring is not seated when they assemble the wheel and that causes the slow leak. I would suggest that you take the wheel apart, place a fine coat of O ring lube onto the O ring so it will remain seated in the groove. Reassemble the wheel and see if it leaks. Hopefully this will take care of your problem.