When you pump too much of it into the pressurized lines, the chemical is forced through tiny nozzles and spray hoses while it's still in liquid form. This then creates the squealing noises, and could lead to serious damage to your air conditioner's moving parts.
If it's overfilled you will need to evacuate some refrigerant from the system, To do this you will need a recovery tank so you won't vent the refrigerant to the atmosphere.
The right way to remove Freon from an AC unit is using a special machine called a reclaimer. The machine captures the Freon and stores it until it is ready to be disposed of appropriately to avoid contaminating the environment.
When an air conditioner is overcharged and has too much refrigerant, it can cause a breakdown and permanently damage the compressor. Adding or removing refrigerant from your air conditioner requires specialized training, tools, gauges and scale, recovery bottles, and a special license from the EPA.
Excess oil in the compressed air supply may overload air oil separators and inline filters and result in damage to pneumatic tools and equipment. If you have overfilled your air compressor oil sump, drain a bit until it comes down to the proper level.
Use a wrench in order to close the low-pressure service valve. Attach a car AC recovery machine at this time. The recovery machine can condense the freon to vapor, removing it from the AC system altogether. Next, reopen the low-pressure port.
Liquid recovery method
As the name implies, with this method you recover the refrigerant in liquid form, so you'll connect to the “high side” of the system (where refrigerant is under high pressure).
In some cases, overcharging your system can cause damage, inefficient cooling, and deterioration in your AC unit.
An excess of coolant has the potential to cause electrical damage in your vehicle. In some cases, the excess coolant can be accommodated by your engine and exits the engine through the overflow hose. However, it is always a good idea to make sure that your coolant isn't above the maximum fill line.
The first sign that there is too much refrigerant fluid in the system, is when there are abnormally high-pressure readings on the pressure gauges of the system.
An air conditioning system overcharged with refrigerant will likely operate poorly, and it may be at risk of breaking down completely or even exploding.
Some of the other underlying issues that might trigger a red light to start blinking on your AC unit thermostat include problems with the high or low pressure or temperature switches, a failed ambient or liquid line sensor or issues with the high or low discharge temperature.
More refrigerant will remain a liquid, affecting the home's cooling and the system's efficiency. Additionally, increased refrigerant remaining in its liquid state means excess pressure inside the AC system, causing the AC system to work harder.
R134a is not an ozone-destroying agent, but it is a greenhouse gas, and is illegal to vent as well.
The compressor and liquid line frosts up while running.
The tank gauge displays a zero when the tank is empty, but as you use the compressor, it will move up. This indicates that the tank is full of pressurized air and ready for your power tools.