New to forum, looking for input on where to introduce PAG oil

[TT_Vert]

I have a 2000 Corvette w/ a leaky seal between the case housings. I am replacing the compressor, the receiver-drier and the accumulator. I will also be flushing the system thoroughly. My question is twofold. According to the service manual I should drain and record volume of oil removed. If >2.0 add that much to new compressor. If >2oz. add 2oz. I will also add the original content of oil plus 2 oz. to the receiver-drier so that may put me at ~6oz. Can i just put the remaining 3 oz. into the condenser? When pulling a vacuum w/ oil in the system will it attempt to pull the oil out as well? Last question may be a bit easier or complicated. My service manual calls for "PAG" oil, the new DELCO compressor calls for "PAG" oil. The compressor doesn't say a thing. I've heard conflicting reports on what viscosity to use for his vehicle. Some say PAG46 and others say PAG150. Most sites say PAG150 but I'm still not 100% certain as there is no well defined answer I can find. Can anyone shed any light on these questions?

Thanks much guys!


Dave

[TT_Vert]

Any input? I've got to get this buttoned back up soon.

Thanks
Dave

[Cusser]

You can add the oil anywhere, it will distribute itself once in operation. If you pour into the compressor directly, be sure to rotate the compressor (inside nut or bolt of the compressor clutch assembly) at least 10 full revolutions before you start the evacuation and charge steps. Also a good time to add a little UV dye, unless you're using PAG oil that already contains UV dye.

Never add ANY sealer, or refrigerant that contains any sealer.

[TT_Vert]

I will be using a PAG oil with UV dye. My biggest question is the viscosity of the oil. I had gone into detail in my original post how there are conflicting pieces of data on this. I believe GM may have used PAG150 at one point but reverted to PAG46 later OR a universal PAG for GM which may be PAG100 but I cannot get any solid info. I don't want to destroy my new ACDELCO V7 compressor w/ the wrong viscosity oil.

Dave

[Cusser]

I believe GM may have used PAG150 at one point but reverted to PAG46 later OR a universal PAG for GM which may be PAG100 but I cannot get any solid info. I don't want to destroy my new ACDELCO V7 compressor w/ the wrong viscosity oil. Dave

Dave - I definitely understand what you say about conflicting information from GM about stuff, seems GM makes things way more complicated than need be. When I replaced the compressor in my 2005 Yukon, turns out that there were different compressors depending upon whether the vehicle had rear AC or not, don't know why GM couldn't just use the same compressor, it's just a pump. Anyway, for sure I'd drain out and measure the amount of oil in your new compressor, and not trust a manufacturer, so you can estimate how much you need to make up the manufacturer total level of 9 oz. And wait until you're more sure about the viscosity of the PAG oil needed.
This site shows PAG 150 !!! https://www.aa1car.com/library/pagoil.htm
So does this http://www.techchoiceparts.com/refriger ... capacities

This site says "For Delphi V-5, V-7, Radial-4, DA-6 and those lightweight H-series axial six-cylinder compressors, use the 125-150 Cst oil if the compressor is old and noisy but still serviceable, to help reduce noise and vibration. If you're installing a brand-new compressor other than A-6 and Radial-4, you can use the 46-53 Cst PAG." https://www.motor.com/magazine-summary/ ... e-picture/

On same Yukon, there are inner reflectors on each of the four doors, to warn drivers approaching from the rear that a door was open. GM used FOUR different parts for this, different one for each door. Most manufacturers would've had one part, reversible for the other side, so only one part would need to be ordered/stocked.

One time I needed a new master cylinder for our 1994 Suburban, and parts store said I needed to know the diameter of my rear drum brakes to get the right one!!!

[TT_Vert]

I though PAG150 until I read that GM switched. I do plan to empty the compressor and put in 2oz just not sure which yet.

Some info I found and posted on my corvette board regarding this.

The system holds 9oz according to the factory service manuals. The compressor is a new OE factory compresor and sadly it says use "GM PAG OIL". I don't see ACDELCO giving me any other info other than what their paperwork w/ the unit states. That's why I'm here asking.

Some conflicting info i have read

The Service Manual lists the part numbers as follows ....

46 (Viscosity) PAG Oil ............... 88901445

R134a refrigerent ...................... 12356150

525 (Viscosity) Mineral Oil ........... 12301108

And they agree with these AC Delco web pages for the A/C system .... see ....

http://www.acdelcotechconnect.com/pi/ac/lubrication.htm

This shows it calls for PAG150 http://www.techchoiceparts.com/refriger ... /chevrolet
PAG 46 here https://www.corvette-web-central.com/co ... oning.html.

[Cusser]

Understand about the confusion.

My one and only experience with a GM dealer was finding out that they "have no idea what was wrong with your sunroof not able to close" on our 2005 Yukon a few years ago, then being reluctant to refund my money ($230), after we had agreed that I'd pay for a FIX and not for a guess. After 3 months and GM intervention I got the refund. I got the $50 "hazardous waste disposal fee" taken off first day of the "repair" because they admitted that they hadn't actually disposed of anything (returned to me the original switch), yet alone anything hazardous. I guess some folks never question. Also the dealership wanted to replace things such as my factory upper radiator hose, even though I had replaced that when I did a water pump a few months earlier; the replacement hose still had the Gates label on it, and the hose clamps were obviously not factory, but I guess they never opened the hood for their "diagnosis".

[GM Tech]

I worked where we made the compressors you are talking about-- viscosity of oil will not cause harm- is not a big deal- they went back and forth- and when push came to shove, they used whatever oil most easily fit the bill- cost wise.

I am more concerned when you say you flushed your system---why oh why--I NEVER flush for a leak failure mode- only for contamination. And what did you flush with- anything but refrigerant is bad--Most all flushes are degreasers, and if you did not get all the flush out, you will damage your new pump by degreasing it. That is why I NEVER flush with anything but 134a refrigerant. When I evaluated warranty returns, I could smell the turpentine smell of various aftermarket flushes, and the pumps were dry inside when they failed due to lack of flush and flushing with non-GM approved flushing agents. Go to the service manual and read what GM has to say about flushing and with what type of flush to use. Don't go by what the guy at NAPA said-- they push aftermarket flushing agents big time. Since you wish not to burn up your next pump, I would be a whole lot more concerned about the flushing agent, then the viscosity of oil I used. Heck, any oil in the compressor is better than no oil, or oil that has been mixed with flushing agent.

No vacuum is able to pull all the aftermarket flushing agent out of a system- been there tried that- does not work.....no amount of blowing clean dry air will pull it all out. Heck, you need to pour it out to get it all, so how can you stand your car on its nose? Flushing with aftermarket flush is only good if you do the individual components on your workbench where you can pour out the remnants.....

As far as where to put the oil in....did you know that every car ever built has its a/c commanded on the very first time at the assembly plant with the entire system charge of oil in its belly? Yes, all 8 or 9 or whatever ounces needed is in the compressor at vehicle start- the compressor manufacturer is the one responsible for the oil in the system. So I really don't think it matters where or how you add oil. I always laugh at those who talk about turning the pump etc-- great- go for it feel warm and fuzzy- but again at the assembly plant- they come on with it all in the belly and they seem to survive ok...

Just my 25 yrs worth of thoughts

[TT_Vert]

Yes, I flushed the system w/ a chemical that is supposedly designed to flush the system which certainly did smell like a degreaser. I did this for two reasons. 1. I had leaked an unknown amount of oil from the system and I had no way of knowing if i was at the correct (or even close to correct) quantity 2. I wanted to get any debris out of system that there may have been. I then thoroughly dried the system w/ compressed air and quickly sealed it up. I have to assume drawing the system down to 350 microns boiled out any and all liquid still present in the system, in fact I cannot see how it couldn't but i'm not a genius when it comes to ideal gas law. I did go through the 3 book service manual and it is not very descriptive about flushing the system actually. Nor does it even mention detail about recharging aside from explicitly saying you have to have x amount of oil in x component. They are very clear about that and I'd assume they are for a reason. I could not imaging having 9oz in the compressor on first startup. Even if you hand rotate the compressor i'd assume hydro lock would be very common. I did disassemble my old compressor to understand more about how it works and all I can say is those things are a work on engineering art!

Dave

I worked where we made the compressors you are talking about-- viscosity of oil will not cause harm- is not a big deal- they went back and forth- and when push came to shove, they used whatever oil most easily fit the bill- cost wise.

I am more concerned when you say you flushed your system---why oh why--I NEVER flush for a leak failure mode- only for contamination. And what did you flush with- anything but refrigerant is bad--Most all flushes are degreasers, and if you did not get all the flush out, you will damage your new pump by degreasing it. That is why I NEVER flush with anything but 134a refrigerant. When I evaluated warranty returns, I could smell the turpentine smell of various aftermarket flushes, and the pumps were dry inside when they failed due to lack of flush and flushing with non-GM approved flushing agents. Go to the service manual and read what GM has to say about flushing and with what type of flush to use. Don't go by what the guy at NAPA said-- they push aftermarket flushing agents big time. Since you wish not to burn up your next pump, I would be a whole lot more concerned about the flushing agent, then the viscosity of oil I used. Heck, any oil in the compressor is better than no oil, or oil that has been mixed with flushing agent.

No vacuum is able to pull all the aftermarket flushing agent out of a system- been there tried that- does not work.....no amount of blowing clean dry air will pull it all out. Heck, you need to pour it out to get it all, so how can you stand your car on its nose? Flushing with aftermarket flush is only good if you do the individual components on your workbench where you can pour out the remnants.....

As far as where to put the oil in....did you know that every car ever built has its a/c commanded on the very first time at the assembly plant with the entire system charge of oil in its belly? Yes, all 8 or 9 or whatever ounces needed is in the compressor at vehicle start- the compressor manufacturer is the one responsible for the oil in the system. So I really don't think it matters where or how you add oil. I always laugh at those who talk about turning the pump etc-- great- go for it feel warm and fuzzy- but again at the assembly plant- they come on with it all in the belly and they seem to survive ok...

Just my 25 yrs worth of thoughts

[TT_Vert]

Yes, I flushed the system w/ a chemical that is supposedly designed to flush the system which certainly did smell like a degreaser (72-75% heptane). I did this for two reasons. 1. I had leaked an unknown amount of oil from the system and I had no way of knowing if i was at the correct (or even close to correct) quantity 2. I wanted to get any debris out of system that there may have been. I then thoroughly dried the system w/ compressed air and quickly sealed it up. I have to assume drawing the system down to 350 microns boiled out any and all liquid still present in the system, in fact I cannot see how it couldn't but i'm not a genius when it comes to ideal gas law. I did go through the 3 book service manual and it is not very descriptive about flushing the system actually. Nor does it even mention detail about recharging aside from explicitly saying you have to have x amount of oil in x component. They are very clear about that and I'd assume they are for a reason. I could not imaging having 9oz in the compressor on first startup. Even if you hand rotate the compressor i'd assume hydro lock would be very common. I did disassemble my old compressor to understand more about how it works and all I can say is those things are a work on engineering art!

Dave

I worked where we made the compressors you are talking about-- viscosity of oil will not cause harm- is not a big deal- they went back and forth- and when push came to shove, they used whatever oil most easily fit the bill- cost wise.

I am more concerned when you say you flushed your system---why oh why--I NEVER flush for a leak failure mode- only for contamination. And what did you flush with- anything but refrigerant is bad--Most all flushes are degreasers, and if you did not get all the flush out, you will damage your new pump by degreasing it. That is why I NEVER flush with anything but 134a refrigerant. When I evaluated warranty returns, I could smell the turpentine smell of various aftermarket flushes, and the pumps were dry inside when they failed due to lack of flush and flushing with non-GM approved flushing agents. Go to the service manual and read what GM has to say about flushing and with what type of flush to use. Don't go by what the guy at NAPA said-- they push aftermarket flushing agents big time. Since you wish not to burn up your next pump, I would be a whole lot more concerned about the flushing agent, then the viscosity of oil I used. Heck, any oil in the compressor is better than no oil, or oil that has been mixed with flushing agent.

No vacuum is able to pull all the aftermarket flushing agent out of a system- been there tried that- does not work.....no amount of blowing clean dry air will pull it all out. Heck, you need to pour it out to get it all, so how can you stand your car on its nose? Flushing with aftermarket flush is only good if you do the individual components on your workbench where you can pour out the remnants.....

As far as where to put the oil in....did you know that every car ever built has its a/c commanded on the very first time at the assembly plant with the entire system charge of oil in its belly? Yes, all 8 or 9 or whatever ounces needed is in the compressor at vehicle start- the compressor manufacturer is the one responsible for the oil in the system. So I really don't think it matters where or how you add oil. I always laugh at those who talk about turning the pump etc-- great- go for it feel warm and fuzzy- but again at the assembly plant- they come on with it all in the belly and they seem to survive ok...

Just my 25 yrs worth of thoughts