Want this question answered?
Refrigerant contaminated with air won't function properly.
If you are referring to automotive refrigerant, the answer is no. Neither refrigerant will work properly if mixed and might damage the compressor or other components.
This is most definitely not a DIY task. To do it properly, you need to first test the purity of the refrigerant, which takes special equipment to do, as does actual recovery and storage of the refrigerant.
Evacuate A/C system and properly dispose of old refrigerant. Replace part. Perform a complete A/C system service (SAFELY & PROPERLY). (Personell certified to handle refrigerant may need to install correct type and amount of compressor oil and refrigerant)
You need a refrigerant recovery system and gauges to do it properly.
Yes
Yes. An ac system will not work properly if over charged.Yes. An ac system will not work properly if over charged.
You don't. You have an EPA certified shop which has the equipment to properly recover, store, and recycle the refrigerant do it.
anything as possibile
By "skipping", do you mean "cycling off and on"? That is caused by low refrigerant pressure. Refrigerant slowly leaks even in an air conditioning system that is functioning properly. It's perfectly reasonable to expect to add a little refrigerant every year or two.
Low refrigerant charge? Temperature control cable not adjusted properly?
malocclusion