Air conditioning system are particular and these system require special tools to perform repairs or refrigerant charging.
When you cant add any freon into the system there is a problem. Probably due to air within the system. If there is air in the system then there is a leak somewhere.
Inspect all the a/c hoses for any oily residue on the hoses. Sometimes the oil residue will have a green tint to it.
During basic a/c service the freon is pulled out of the system and then a vacuum pump is connected to the a/c system to remove any air in the system. Then you can recharge the a/c system.
Hope this answered your question.
Tuesday, June 10th, 2014 AT 1:55 PM