So after i had the system converted been driving for about 2 days and the AC works....sorta. I would say its running at about 50% capacity. My next issue is whenever i turn the car off after the AC has been running there is a hissing noise from under the hood that last about 10-20 seconds then stops. Is this normal or the old AC system developing leaks?

 

I don't suppose you know what the gage reading were after the system was converted? If so then just put a set of AC gages back on the car and see what the readings are. Also sometime the hissing can be water/condensation from the AC lines hitting the exhaust system or just internal system pressure. I would check the system with gages and go from there.

 

The hissing is the high pressure side and low pressure side equalizing.
Ed