There are UV leak detection kits you can purchase at all most any automotive store which have UV dyes, lights and glasses that will help you locate a leak.
You have to have a freon leak detector. Are you can put freon dye in the system and find a leak that way.
The easiest way is to add freon and an oil with a dye additive and use a florescent light and yellow goggles to pinpoint the leak/leaks........
Sorry, but nobody can answer that question until you have found the leak and described where it is or maybe posted a pic.
A leak is the only way to loose volume of the freon charge. Freon is in a sealed system and it does not get used up. If your system is tight the freon will last forever. However a restriction in the freon lines can cause the freon pressure on the low side to look like it is low but the freon is really stacking up in the condensor.
Depending on the equipment the mechanic has, it may be the only way he can find the source of the leak.
There are 2 , common, ways to detect leaks. An electronic leak detector and dye. Sometimes both are needed. Of course the system has to be full of freon to for the dye to leak out or for an electronic detector to find a leak (just like finding an air leak in a tire). If the leak is at a connection, you may be able to just replace O rings, if a component (Like the compressor, condensor, evaporator) is leaking it will need replaced. If the system has freon in it, the law says to recover it with a recovery machine. There are 2 , common, ways to detect leaks. An electronic leak detector and dye. Sometimes both are needed. Of course the system has to be full of freon to for the dye to leak out or for an electronic detector to find a leak (just like finding an air leak in a tire). If the leak is at a connection, you may be able to just replace O rings, if a component (Like the compressor, condensor, evaporator) is leaking it will need replaced. If the system has freon in it, the law says to recover it with a recovery machine. There are 2 , common, ways to detect leaks. An electronic leak detector and dye. Sometimes both are needed. Of course the system has to be full of freon to for the dye to leak out or for an electronic detector to find a leak (just like finding an air leak in a tire). If the leak is at a connection, you may be able to just replace O rings, if a component (Like the compressor, condensor, evaporator) is leaking it will need replaced. If the system has freon in it, the law says to recover it with a recovery machine.
It depends on what is wrong with it. It probably has a freon leak. Add some freon, and listen for a leak. Always charge the system through the low side of the system. If you don't hear a leak, then add the required capacity, and the unit will last through the summer, if there is not a component failure. The best way to check the system is with air conditioner pressure gauges.
There are lots of places that can leak freon and some can be sealed with stop leak. The only way is to try it.
Freon (R-12) is way too expensive as it is no longer in production. Have it converted to use R-134a. I suggest a visit to a professional A/C shop as the fact that you need to add refrigerant indicates you have a leak that needs repairing. It is illegal to add refrigerant to a system with a leak without first repairing the leak.
with the use of skilled professionals to dive the pool and pressure test the lines
The best way to find your vacume leak is to start it up and spray starting fluid around and when you hear the engine rev that's where the leak is at
Unfortunately, opening up as much wall as necessary is easiest way to find leak.