Nissan Repair: Replacing an ac condenser, ac condenser, vacuum pump

Question
When replacing a ac condenser on a 1997 200sx do you have to drain the fluids before adding the freon? How long should it take for the car to take the new freon? How long should it take for the ac to start blowing cold again?  

Answer
Crystal,

If the condenser is defective, like being plugged or if it has a hole in it then a replacement is in order.  It is a matter of disconnecting the lines to the unit and unbolting it from the car.  If the system was out of R-134 then it is just a matter of bolting the new one in and connecting the lines with new o-rings.  Then, get a vacuum pump to evacuate the system for a minimum of an hour to get all the moisture out of the system.  Also, if the system was open for a long time the dryer should be replaced too.  Now, that the system is evacuated you should add the amount of refrigerant indicated on the hood sticker.  It should hold about 2.5 pounds of R-134.  A couple of hours to remove and replace the condenser and another hour to evacuate the system along with aobut fifteen minutes to charge the system.