I have a new Campbell Hausfeld 60 gal. compressor that doesn't want to
maintain any pressure over a period of time. If I run the compressor
and bring it up to pressure, then turn off the motor, within 48 hours
the pressure is down below 20 psi. Obviously, there is a leak
somewhere in one of the connections, or in the tank itself.

I've talked to a contractor buddy that uses several small portable
compressors often, and he tells me that this is normal - not to worry
about it. To me, it seems wrong. I can see if the pressure dropped
down a bit over time, but to completely empty in 2 days?

So, what is a reasonable expectation for a 60 gal compressor holding
pressure?

The tank has a big sticker claiming that it includes on site warranty
service from the manufacturer, should I try to take them up on their
offer?