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Winter ac charging

Posted: Sun Jan 12, 2025 7:49 pm
by Duane
Have the engine out of my wife's 2012 Equinox 3.0 for rebuild. Ac system was opened and am starting to put it back together. Question is I am working outside here in Ohio with 3.5" of snow on the ground and temps around freezing how or what would be the way to charge the system? Can you put pag oil in it, pull a vacuum, and pull the compressor relay so it will not engage and drive the car till we get warmer temps or add r134a using a ready heater blowing heat into and under the car to warm the front of the car and add r134a till fully charged? Would only be able to add the proper amount of r134a, 1.43#, and check the pressures in the spring when the weather warms up. I would like to do this myself instead of taking to a shop that is only 50-60 degrees. I have the gauges and vacuum pump. Thank You in advance for the help with this, have learned a lot reading this site.

Duane

Re: Winter ac charging

Posted: Mon Jan 13, 2025 8:28 am
by JohnHere
Hey, Duane. Appreciate your kind comments.

It's tough working outside in your area of the country in Winter. It's unusually cold here as well.

That said, I would delay working on the A/C system until around June 1 or whenever the temperature in your area rises to about 80°F. At freezing temperatures—Reddy Heater or not—you'll have a very hard time getting the refrigerant into the system unless you can get the vehicle into a heated garage someplace and also warm-up the refrigerant cylinder or small cans.

Additionally, I recommend not leaving the system under vacuum until Spring because if it should develop a leak, a system left under vacuum will just pull-in air and moisture, which as I'm sure you know, isn't a good thing.

You could install the full oil charge now (specs call for 5.0 fluid ounces of PAG-46), delay the evacuation and recharge until the weather warms, and drive the car in the meantime. The A/C system won't run anyway with no refrigerant in it, so there's no real need to remove the compressor relay unless you'd feel more comfortable doing so.

Has the A/C system been left open to the atmosphere while working on the engine? If it has, then you'll have more work to do—that is, thoroughly flushing the system of the old oil and/or contaminants. If you're reusing the original compressor, don't use any type of solvent to flush it out. Use only PAG oil for that purpose. It'll be best to wait until Spring to do the flushing as well, if needed.

In any case, be sure to replace the accumulator or receiver/dryer, whichever applies, as well as the orifice tube if your vehicle has one.

Your specification of 1.43 pounds net weight (22.88 ounces) of R-134a matches the specs that I have.

How many miles has this vehicle logged?

Re: Winter ac charging

Posted: Mon Jan 13, 2025 7:01 pm
by Duane
Thanks for the response. The system has been open about 5 weeks, I know is not good but it takes a while to get the motor work done. The vehicle has 200,000 miles on it. I have taken care of it with regular service, the ac system worked when I tore it down.

I flushed the evaporator and the low and high pressure lines attached to it. Have gotten a new condenser/dryer, but the system is still open so should I wait to put the new condenser/dryer on when the weather warms up? Put plastic bags over the hose ends to keep rain and snow out of them, they will need to be flushed. The way I understand what you said was to charge the compressor with the pag oil and put the system back together. Then in the spring tear it back apart and flush, install new condenser/dryer, assemble, pressure test, vacuum, and charge with refrigerant.

Re: Winter ac charging

Posted: Tue Jan 14, 2025 7:24 am
by tbirdtbird
Totally agree with John.
I would not try to do anything with the components now. Seal up the ends of everything as best you can and then when the weather is much warmer reassemble components, flushing as needed. Is this an orifice tube system? If so was there a lot of crud on the OT? If so, this indicates a compressor beginning to fail. The OT should be totally free and clean when you removed it.
With that kind of mileage, I would definitely replace the comp, as its days are very much numbered.

Re: Winter ac charging

Posted: Tue Jan 14, 2025 8:38 am
by JohnHere
Looking a little deeper into the specs, Denso is original equipment, and the system has an electronic variable-displacement compressor. It also has a TXV, not an OT, as well as an integral (with the condenser) R/D, and no accumulator.
Duane wrote: Mon Jan 13, 2025 7:01 pm I flushed the evaporator and the low and high pressure lines attached to it. Have gotten a new condenser/dryer, but the system is still open so should I wait to put the new condenser/dryer on when the weather warms up? Put plastic bags over the hose ends to keep rain and snow out of them, they will need to be flushed. The way I understand what you said was to charge the compressor with the pag oil and put the system back together. Then in the spring tear it back apart and flush, install new condenser/dryer, assemble, pressure test, vacuum, and charge with refrigerant.
For now, definitely seal-up all the components as air-tight as possible. The new condenser assembly should have come factory sealed. I would keep it that way until ready to install it.

Your understanding is partially correct. Since the system has been open to the atmosphere for quite a while, I would flush the evaporator and lines again in the Spring, then complete the other work you mentioned to get the system back in operation.

If the compressor is original, I wouldn't bother trying to flush and re-use it. With that much mileage on it (if it is in fact the original compressor), I'd just replace it with a new unit (not a rebuilt). Usually, new compressors come pre-filled with the recommended amount of oil. To ensure the new compressor has the correct amount and type of oil in it, best practices suggest draining the pre-filled oil and replacing same with 5.0 fluid ounces of PAG-46. Many professionals prefer to use double-end-capped PAG oil (DEC-PAG) because it isn't hygroscopic (doesn't absorb moisture).

Since you're basically rebuilding the entire system, be sure to replace all the o-rings and gaskets. I prefer to use Nylog Blue on every o-ring, gasket, and connection point to help ensure a leak-free system.

Re: Winter ac charging

Posted: Tue Jan 14, 2025 2:51 pm
by Duane
Again many thanks for the guidance you have given me. I will put the system back together that will be the best way to keep dirt and moisture out of it.
Yes the new condenser/dryer has plugs in it and will get installed in the spring, along with new compressor.
The compressor is a AC Delco 7SBH17H. I see them on ackits,com but it is $100.00 more that the price rock auto has them. I cannot read the sticker under the hood for the volume of pag46 oil the system requires. All data under hvac specification shows the full volume of system at 4 oz, John you stated to put 5 oz in it. Would a little more be a bad thing?

I see this site takes donations to help pay the bills, correct?

Greatly appreciate your help.

Re: Winter ac charging

Posted: Tue Jan 14, 2025 4:02 pm
by Tim
Duane wrote: Tue Jan 14, 2025 2:51 pm The compressor is a AC Delco 7SBH17H. I see them on ackits,com but it is $100.00 more that the price rock auto has them.

I see this site takes donations to help pay the bills, correct?

Greatly appreciate your help.
Was it item to item? You have to be sure our prices are for the same "quality" item. Not just an application item. It could also have been an outdated price on our part.

New ACDelco is higher than Rock, on ACKits.com. I'm looking at the landed cost of the ACDelco. Not much wiggle room.

The site accepts donations.

Re: Winter ac charging

Posted: Wed Jan 15, 2025 8:35 am
by Duane
Tim, Thanks for trying. Sent a little something to help the site for the help it gave me.

God Bless

Re: Winter ac charging

Posted: Wed Jan 15, 2025 9:32 am
by Tim
Duane wrote: Wed Jan 15, 2025 8:35 am Tim, Thanks for trying. Sent a little something to help the site for the help it gave me.

God Bless
Thank you!

If half of the people who used this site helped with $10.00, it would cover the yearly cost w/o a problem.

Re: Winter ac charging

Posted: Wed Jan 15, 2025 10:18 am
by JohnHere
Duane wrote: Tue Jan 14, 2025 2:51 pm ... . I will put the system back together that will be the best way to keep dirt and moisture out of it.
Good idea...an alternative to sealing-up each opening.
Duane wrote: Tue Jan 14, 2025 2:51 pm I cannot read the sticker under the hood for the volume of pag46 oil the system requires. All data under hvac specification shows the full volume of system at 4 oz, John you stated to put 5 oz in it. Would a little more be a bad thing?
AllData says 4.0 fluid ounces, but 5.0 fluid ounces is what I found in four additional resources to which I have access. All four listings show the identical amount for a 2012 Equinox for both the 2.4L and 3.0L engines. Researching a little more, I discovered that the 4.0 oil specification is for the 2010-2011 Equinox for both engines. My guess is that the AllData specification is a misprint, so I would go with the 5.0 fluid-ounce specification.

Thanks again for your kind support.