Yes.
You can find a Freon leak in a home Ac unit by using a leak detector. These instruments are capable of detecting trace amounts of Freon and pinpoint leaks.
yes there is a seal on the front of compressor that can go bad and leak freon.
If it leaks it leaks. Central units are self contained with no external rotating shaft seals to leak. If the tech came out and added freon without detectng the leak, either he did exactly what you directed, or he is a BS artist hoping for a repeat job.
No
It can, in some cases.
No, the leak is propably the compressor shaft seal which is behind the clutch.
Freon can leak. Since it will do so in the form of an invisible, odorless gas, it is very difficult to observe such a leak.
With a Halogen electronic leak detector.
Freon is odorless, but it is possible to smell the refrigerant oil that could also be leaking.
Yes. Or leak check with nitrogen.
It a word, no. Without a leak, the freon level in your unit should stay the same for years and years.
There are a few reasons your AC might not get very cold even though the Freon is fine. You could have a leak in your line.