Charlie S. wrote:
I have a Home Depot type of dolly that has a flat tire. Tried
pumping air into the valve... couldn't get any pressure in the tire.
Doesn't seem to have any nails in it. Couldn't see any tube inside
either. Reminds me of a regular car tire.
I know it sounds silly, but I thought of bringing it down to a tire
shop and having them look at it. Or, would I be better off taking
off the wheel and buying a new wheel/tire unit?

The tire thickness and wheel build is similar to that of a regular
car tire. Get the feeling I would need a special machine to take it
off and put it back on again.

As another poster pointed out, you've got to seal the tire against the rim
before it will hold enough air to allow inflation.

There are two fixes: (1) Monitor the tire(s) every week and keep them
inflated, or (2) Find an inner tube that will fit.