Bob,
I have found that small leaks are hard to find with high pressure in
the
system. Let it down to 20# or less, then you will see the bubbles
foaming
at the little ones. Too much press. blows away the suds before you
notice them.
RichD

Bob Engelhardt wrote:
I have an IR home-shop compressor (20 gal, 1 1/2 hp) with a leak. I
just measured & timed it: in 17 hours the pressure dropped from 100 psi
to 55. This means the compressor runs several times a day just to
maintain pressure. It is loud, so this is annoying.

In an attempt to find the leak, I sprayed soapy water on EVERYTHING: the
entire tank, the drain fittings, the "Christmas tree" fittings (pressure
switch, guage, etc). I even disconnected the pump output line to see if
the check valve was leaking back into the pump. I found a small leak in
the pressure guage connection, which I fixed (tightened). It STILL
leaks (but not the pressure guage)!!

Now it has become a challenge. I've GOT to find that leak! Before I
start taking parts off to eliminate them as leaks, does anybody have any
tips/tricks for finding leaks that might save me the work?

Thanks,
Bob