Ok, this is how to pull a proper vacuum and re-charge your air conditioning system with refrigerant.
This is crucial that you do a good job here; this is where you show your worth. And this step decides how long your compressor will last, so please pull a good vacuum.
Grab a set of digital gauges or at least a set of analog gauges and a micron gauge and a vacuum pump full of fresh oil.
Hook up the Digital gauges and the vacuum pump to the air conditioner.
The middle and usually yellow hose goes to the vacuum pump, the left and usually blue hose goes to the thicker suction line and the right, normally red hose goes to the thinner liquid line.
Now open the gauges open the hoses and open the vacuum pump.
Turn on the vacuum pump and double check every access or hose to be sure there all open and your pulling a vacuum. Also double check that all your connections are tight.