[sammyg2]

I have that 2.5 hp 8 gallon air compressor in my garage.
I've had it for about 4 years, and up until recently it was completely trouble-free.

A metal cap on the relief valve broke off rendering the machine un-useable. the cap was made of pot metal and not easily replicated or replaced.
I went to the harbor freight website and found the air compressor and clicked on user manual. There in PDF form it showed an exploded view and a toll free phone number. I called and ordered a complete relief valve assembly. It cost $1.85

delivery is kind of slow because I think it has to come from over-seas but they also said that if I would like they can check their local warehouse to see if they have a used part that they can ship in less than a week. Not bad.

The machine is very handy, not exactly quiet but not overly noisy. It will have trouble keeping up with a 1/2" impact gun or peanut grinder so if you plan to run larger power tools it may not be the best choice. It will run them, but not continuously. It builds up 125 psi and has an adjustable regulator.
It also takes up very little space if that is a concern.

Yes you can get a better machine for three or four times the price, but for under $100 it is hard to beat.