It is common place to call for a part for a particular model and be given several choices, especially when working with air conditioning. Before calling for parts, get the name of the manufacturer of the air compressor off the old compressor. It is also important to know that it is illegal to release Freon into the atmosphere. Unless the compressor or another component leaked all of the Freon out of the system, an air conditioning reclaimer is needed to capture the Freon.
Lift the hood and remove the serpentine belt by loosening the belt tensioner with the appropriate size wrench. The tensioner is spring loaded so just put the wrench on the bolt in the tensioner pulley and pry against the spring tension until it is loose enough to get the belt off.
Check to see if the system is pressurized by momentarily pushing in on the small, low side pressure valve. There are two Schrader valves. One is the low or suction side and the other is the high side or high pressure side. They are two different sizes for identification. The low side with the lowest pressure is the smaller of the two valves. Use something small like a nail or small screwdriver and briefly tap the head of the Schrader and see if Freon escapes. If it does than the system has to be evacuated with a reclaimer. If you need a reclaimer, you will have to bring the car to a shop.
Remove the wire and plastic connector to the compressor clutch. Remove the low and high side manifold at the back of the compressor by removing the center bolt. Remove the four bolts holding the compressor. Lift the compressor out.
Look at the new compressor and make sure it is the same as the old compressor. Look at the wire for the compressor clutch and make sure it has the same connector. Read the label or tag on the compressor to see if it has a full charge of oil. Some compressors come with a full charge, others do not and have to have oil added.
Assuming that the compressor has no oil charge, take the red caps out of the manifold ports. Remove the plug on the side of the compressor and slowly pour 6 ounces of refrigerant oil in the port while very slowly turning the compressor clutch with the other hand. If the compressor has an oil charge, skip this step.
Replace the plug in the oil hole and turn the compressor clutch ten to twelve times. Stand the compressor up on the clutch and let it sit for ten minutes to soak the front seal of the clutch.
Install the compressor and tighten the bolts. Plug the wire connector into the compressor clutch on the top of the compressor next to the clutch in its slot.
Inspect the o-rings on the manifold hoses and oil them with refrigerant oil. Replace if necessary. Install the compressor manifolds and tighten the center bolt. Reinstall the serpentine belt.
Install a vacuum pump to the Schrader valves and let it vacuum the system until it reaches 30 inches of vacuum. Once it hits 30 inches of vacuum, vacuum for another 20 minutes to rid the system of moisture.
Remove the vacuum pump and install the air conditioning gauges to the low and high side ports. The blue line goes to the low side or suction side and the red line goes to the high side or hi pressure port. Make sure the valves on the gauges are shut off and turn the valve on the bottle of Freon on. Loosen the feed line to the gauges at the gauge just enough to let the air in the line out.
Look at the sticker or decal on the truck under the hood--it will have the amount of charge for that particular vehicle. If you are using a reclaimer dial in the amount at this time and charge the system.
If you are filling from a bottle then just turn the low side valve on the gauge to "ON" and listen closely to the low side pressure valve on the accumulator to click. Once you here the click shut the valve on the gauge off. The system has just enough pressure to turn the compressor on.
Start the car and turn the air conditioning and the fan on high. Also put the vent selection on recirculate. Put one hand on the low-side line near the accumulator. This is the larger of the two lines. Turn the low side or blue valve open and feel for the line to suddenly get ice cold. As soon as that occurs, shut the valve on the gauge. Let the air conditioning system stabilize for 5 minutes and then look at the gauge readings. When the system is fully charged, the readings should be 30 to 35 lbs. on the low, or blue, side and 210 to 240 lbs. on the red, or high, side. Anything above that is overcharged and anything less is undercharged, assuming everything else in the system is working properly.
