Swapping out a\c compressor and drier

Account for all oil contained in the parts you remove. Add new oil if required, especially if the oil leaked anywhere. Make sure if you add oil that you get the right oil for use with the HC134A refrigerant. This often winds up being a guestimate as the only way to know exactly how much oil to use is by flushing the entire sealed system and starting fresh. This requires special equipment though. Do NOT use compressed air!

When the sealed system is back together, attach a manifold gauge set to the low and high side service ports and evacuate to better than 29" Hg. This step is particularly important as the vacuum will get any water in the system to be vaporized and expelled. The desiccant in the receiver/drier will trap moisture but it is best to start as clean as possible. Moisture will usually choke the expansion valve and cause problems. Depending on your vacuum pump, it should take about an hour to properly evacuate the system. Close both high and low side valves on the gauge manifold. and watch the compound (low side) gauge to verify that the system is holding vacuum.

Remove the hose from the vacuum pump and connect to a can of refrigerant. Open the valve on the refrigerant and carefully loosen the hose fitting at the manifold side to purge air from the hose. Tighten the fitting again and start charging the system by again opening the high and low side manifold valves. Refrigerant is added by weight according to the spec for your model. Charge with vapor only! Can must be upright or you will get liquid which flushes oil from the compressor and will kill the bearings on startup.You can hasten charging by putting the refrigerant in a warm water bath. When you can't get anymore '134 to flow (and have not reached the specified weight of gas to add) close the high side manifold gauge, start the engine and turn on the AC. Compressor suction should now draw in the remainder of the charge. Make sure that the high side valve is closed before starting engine. Depending on your equipment, a can may rupture from failing to close the high side valve.

When done, turn off the engine and wait for the pressures to equalize and disconnect the gauge set quickly to minimize gas leak. I hold down the hose to keep the seal while removing the fitting and then pull back quickly.

Wear safety glasses when working with refrigerants. Should you get a leak of liquid spray on you, it freezes tissue on contact.

There are shortcuts but they do have consequences. Hope this either helps you or convinces you to get it done professionally. Nothing wrong with replacing the components yourself and then having the evacuation/recharge done by a garage.

Oppie

Account for all oil contained in the parts you remove. Add new oil if required, especially if the oil leaked anywhere. Make sure if you add oil that you get the right oil for use with the HC134A refrigerant. This often winds up being a guestimate as the only way to know exactly how much oil to use is by flushing the entire sealed system and starting fresh. This requires special equipment though. Do NOT use compressed air!

When the sealed system is back together, attach a manifold gauge set to the low and high side service ports and evacuate to better than 29" Hg. This step is particularly important as the vacuum will get any water in the system to be vaporized and expelled. The desiccant in the receiver/drier will trap moisture but it is best to start as clean as possible. Moisture will usually choke the expansion valve and cause problems. Depending on your vacuum pump, it should take about an hour to properly evacuate the system. Close both high and low side valves on the gauge manifold. and watch the compound (low side) gauge to verify that the system is holding vacuum.

Remove the hose from the vacuum pump and connect to a can of refrigerant. Open the valve on the refrigerant and carefully loosen the hose fitting at the manifold side to purge air from the hose. Tighten the fitting again and start charging the system by again opening the high and low side manifold valves. Refrigerant is added by weight according to the spec for your model. Charge with vapor only! Can must be upright or you will get liquid which flushes oil from the compressor and will kill the bearings on startup.You can hasten charging by putting the refrigerant in a warm water bath. When you can't get anymore '134 to flow (and have not reached the specified weight of gas to add) close the high side manifold gauge, start the engine and turn on the AC. Compressor suction should now draw in the remainder of the charge. Make sure that the high side valve is closed before starting engine. Depending on your equipment, a can may rupture from failing to close the high side valve.

When done, turn off the engine and wait for the pressures to equalize and disconnect the gauge set quickly to minimize gas leak. I hold down the hose to keep the seal while removing the fitting and then pull back quickly.

Wear safety glasses when working with refrigerants. Should you get a leak of liquid spray on you, it freezes tissue on contact.

There are shortcuts but they do have consequences. Hope this either helps you or convinces you to get it done professionally. Nothing wrong with replacing the components yourself and then having the evacuation/recharge done by a garage.

Oppie

I was going to install the components and then take it to a garage to have it charged, after reading this post, I think I will have them do it all. Thanks so much Belle