I have stuff in my refrigerant. Now what?

[RalphARoni]

I have a '96 Geo Tracker. It is a black convertible with a single layer top. It gets hot inside. I recently replaced the compressor because it leaked.I did add 2 1/2 oz of pag. The specs call for 3 1/2 but I know there is some left in the system. I also replaced the high side hose from the compressor because it leaked. I no longer have to add refrigerant. Right now I am on the Florida keys. Today it is 80f and the air going into the system (on recirculate) is 90f. The air coming out of the vents can be as low as 61f but not so low when stopped or at lower speeds. The low side reads 30psi. If it gets higher it will cycle. It gets the car temp down to 80 but it is dry and blowing so it seems OK. I don't think it will be so good at 90f though.

Because it was open to air while replacing the compressor and pipe I plan to replace the dryer, draw a vacuum and refill with the correct 24oz by weight. What I don't know is what lurks in the system and how it will effect the end result. Over time I have added refrigerant often as well as an additional 2 oz of PAG out of fear of wrecking the compressor. I once used 3 oz of a 7 oz can of stop leak too. Will having the system emptied remove any of that? Is there a simple way to clear it out? Is absolutely necessarily necessary to flush it? A pro will want more than the car is worth. Can I just pull the vacuum, hope the PAG is close and fill it? What are my chances.

Should I replace the expansion valve? Some say to do it routinely. It requires the removal of the evaporator.

[JohnHere]

I recently replaced the compressor because it leaked.I did add 2 1/2 oz of pag. The specs call for 3 1/2 but I know there is some left in the system.

Did the new compressor come pre-charged with oil? If so, did you pour it out and measure it before adding back the 2-1/2 ounces?

I also replaced the high side hose from the compressor because it leaked. I no longer have to add refrigerant.

Do I understand correctly that you already recharged the system without evacuating it and changing the receiver/dryer?

Today it is 80f and the air going into the system (on recirculate) is 90f. The air coming out of the vents can be as low as 61f but not so low when stopped or at lower speeds. The low side reads 30psi. If it gets higher it will cycle. It gets the car temp down to 80 but it is dry and blowing so it seems OK. I don't think it will be so good at 90f though.

By "the air going into the system (on recirculate) is 90f," do you mean the ambient temperature is 90 degrees? A 61-degree vent temperature with the cabin cooling down to only 80 degrees is insufficient and indicates that something is still very wrong.

Because it was open to air while replacing the compressor and pipe I plan to replace the dryer, draw a vacuum and refill with the correct 24oz by weight.

Actually, you should have replaced the R/D, evacuated, and recharged the system the first time because you now have air and moisture in the system from it being open for a while.

What I don't know is what lurks in the system and how it will effect the end result. Over time I have added refrigerant often as well as an additional 2 oz of PAG out of fear of wrecking the compressor. I once used 3 oz of a 7 oz can of stop leak too. Will having the system emptied remove any of that? Is there a simple way to clear it out? Is absolutely necessarily necessary to flush it? A pro will want more than the car is worth. Can I just pull the vacuum, hope the PAG is close and fill it? What are my chances.

Adding stop-leak or sealer is not advised because it invariably clogs things up and creates even more problems than you had before. Recovering the charge won't remove the old oil (if any) and certainly not the stop-leak. You can solvent-flush the evaporator and lines, flush the compressor several times with PAG oil only (no solvent), and just replace the condenser. Then start from scratch by adding the full amount of PAG oil, then evacuate, recharge, and hope it works. Since you now have sealer in the system, best practice would be to replace everything, though.

Should I replace the expansion valve? Some say to do it routinely. It requires the removal of the evaporator.

With sealer in the system, it would be a good idea to replace the TXV as well. Best to install an OEM unit, though, rather than aftermarket because the latter often don't work right.