You need to measure the pressure in the system and have the car windows rolled down and air on high to make it perform. Here's what you want the system to do. The compressor will cutout when either switch is tripped. This means a moderate amount of Freon is supposed to be in the system to avoid tripping the switches. The openings are usually about. Make sure it holds pressure. It really isn't that hard to do.
Nitrogen an inert gas , is best because it doesn't introduce moisture into the system. If the compressor does not start, check the fuse or add Freon. . At this point your dryer tank will frost or sweat, the lines from the tank will frost too. There are 2 pressure cutoff switches. Be sure to clean all hose assemblies internally prior to installing your new compressor.
The compressor will not run if there is too much pressure. When you have your pressure right everything should work providing the system was properly prepped before the Freon was added. You need to do this a couple of times. Then recharge the system with the proper freon and oil to the system specified levels. Measure and remove Freon to cancel the high pressure switch. In simple terms, Freon is a gas that expands and if you add it in Cold weather it will expand and have higher pressure and be overfilled in Hot weather.
There is a high pressure side and low pressure side to the system. Your compressor will not start if the pressure is below the Low pressure minimum. It's virtually mandintory to replace the orifice tube or expansion valve. After you have cleaned, inspected and replaced all the parts, you connect the vacuum pump and remove the air from the system. Typically, the condenser should be flushed to remove any debris or contaminated compressor oil. The idler pulley is the one with the spring. Flush both ways until the flush agent exiting is clean, you will need to remove the hose assemblies to do this.
Loosen the nut and remove the spring then you can remove the timing belt. Hope this helps, good luck. Use approved flushing agents aresol or liquid pour types , that evaporate quickly and don't leave any residue in the system. If don't replace your accumulator or drier you will probably void your compressor warranty. The Freon can remove the most heat in this condition.
If you want to change the timing belt you need to remove the plastic rock guard under the motor on the passenger side. Not doing this could contaminate your new compressor. You can loan tools from Autozone or Oreillys with a deposit. It should be changed every 30,000 miles. Your system will use R134a freon. .
. . . . . .
. . . . . . .