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Replace AC Compressor

I am told by the local auto AC shop that the compressor on my 98 Regal leaks and needs replaced. Their price is $800 for the job. Is it practical to have the system professionally evacuated, install a rebuilt compressor ($219), then have the system professionally recharged? How difficult is it to remove and replace the compressor? Is it worth the risk to get a used compressor from the junk yard? Any thoughts or advice will be appreciated.

When a compressor for an AC system is replaced, and if it’s other than just a clutch bearing failure, the entire AC system needs to be flushed. Flushing requires that a special solvent is used to remove any debris from the major AC components, condenser, evaporator, and the hose assembly. And to properly flush a condenser requires removal so the inlet/outlet is orientated in the vertical position so the compressed air pushes out all the solvent and any debris. This is all done to ensure the new compressor isn’t destroyed from anything left in the AC system.

Then a vacuum pump is connected to the system to evacute all the air and moisture.

Then the system is recharged with refrigerant.

So if these steps aren’t followed, you can end up with a trashed compressor. Be it rebuilt or used.


If the compressor is just leaking and has not upchucked its guts into the system, you could have the AC shop evacuate any remaining refrigerant from the system and bring the system up with dry nitrogen or another gas of their recommendation. Then you can install the rebuilt compressor. Follow the procedure for having the correct amount of oil in the compressor.

Ask the AC shop if they would recommend replacing the receiver/dryer or other component(s). If you do replace the receiver/dryer install that last and do it as quickly as possible.

Take the car back to the AC shop for leak testing. For expediency you might let them correct any leaks found. Then they can be evacuate, charge, and test the system. You might want to get an estimate from them before you start.

You could use a recycled compressor but you are risking having to pay a second time if the compressor turns out to be bad. Also the compressor will have been exposed to unknown elements for an unknown length of time. Add to that the need to drain the oil and refill with the same amount as was drained from the original compressor. Use new as the oil becomes water ladened over time.

It is a doable project but the total cost may be close to what the shop is charging.

I find it amazing that you can buy a complete 5500 BTU window air conditioner for your home for $139 but replacing just the compressor in an automotive unit costs $800…

Flushing: The removal of all the old oil/debris from the AC system.

Evacuation: The removal of all air/moisture from the AC system.

Reclaiming/recycling: The removal of all refrigerant from the AC system.

Recharging: The introduction of refrigerant into the AC system.


The accumulator/drier and the orifice tube should also be replaced if the compressor has been wiped.

If the compressor has not been wiped and this is a matter of a simple seal leak it’s possible to replace the shaft seal, clutch bearing, and give it a shot like that.