360 A/C Oil Question

I just had my compressor rebuild by Mobile Air Parts in Georgia. It came back quickly and looks great. I hope to install it this weekend when I finish the throw out bearing replacement and and a belt service. I purchased PAG-46 oil for it. Online this looks like the proper replacement for the oil that was originally used in it. It calls for 265 cm^3 of oil for a new system. That is about 9 oz of oil for an empty system. I flushed the line running back to the compressor from the dryer which I also replace. The guy that rebuilt the compressor said to add 3 oz to the drain on the compressor and not through the inlet and outlet ports. Any ideas on how much oil I should add to the rest of the system since it appeared that a decent amount was flushed out from the system?

I don't have an injection canister to inject it into the system using the A/C gauges. I saw someone on YouTube draw a vacuum and then enter it through the high pressure side by cracking the valve. Anyone see an issue with doing it this way or have you had success doing this? Any help would be helpful.

 

That's not the correct oil.

PAG-46 (like what you'd use on a Toyota A/C system for example) has a lower viscosity index than what Ferrari specifies. They list SD2-231 oil in the shop manual, which is equivalent to PAG-150, not 46. While PAG-46 may very well work, PAG-150 has a higher VI (around 20% higher) and thus is a more stable oil under temperature changes. Given the high heat levels generated in the 360 engine compartment, I think I'd stick with PAG-150 myself.

Here's the oil I use - which has UV dye in it:

https://www.amazon.com/TSI-Supercool-P150-32D-150-Viscosity-Plus/dp/B00CFQQRWC

If the compressor is dry, you should add the oil directly into the compressor (see below). Attempting to introduce oil via either the L or H side of the system isn't how I'd go about it - oil goes into the compressor. Make sure you pull a vacuum on the entire system and monitor the vacuum (vacuum pump off / manifold sealed) for at least 60 minutes for any system leaks.

Then pull another vacuum for an hour before introducing the R134a. Also, make sure you use a good quality refrigerant. I use Johnsen's brand myself. Also, most cans today use a reseal top, which can be a nightmare to deal with - make sure you visually see the refrigerant going in and weigh the can before and after introduction to make sure. Turn the cans upside down and if you are using the resealing valve version, it can be real tricky to get the refrigerant to flow initially. Be careful not to accidentally introduce air into the system dealing with everything and/or when switching cans (when using multiple cans of R123a)

Do you have any previous experience recharging an A/C system? It's not all that difficult, but generally the first time you do it it can be a tricky until you get the hang of what to watch out for. Also, what manifold gauge set are you using for all this and what vacuum pump? You want to use a gauge set that shows an accurate scale on the vacuum side especially, so that you can confirm you're not only pulling a good vacuum, but that it holds for an hour to confirm the system has no leaks.

I'll attach some material relative to this from the 360 WSM manual, but putting the oil in the compressor is really the only method I'd recommend, Ferrari or otherwise.

Have fun and good luck!

Ray



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BTW, putting compressor oil in via the lines is typically only for topping off the oil a little bit. In other words, it's mostly done when you are recharging the refrigerant and some of the compressor oil comes out in the process of removing the refrigerant. In that case, you can use a T fitting canister affair to re-introduce a few ounce of lubrication (PAG-46, etc.) back into the system to help ensure there is no drop in the overall system oil level.

However, for totally filling the system up from dry (e.g. when you rebuild the compressor, as you have done), you need to directly fill the compressor prior to re-installation. In that case, all the oil goes directly into the compressor. If you try to fill the entire system w/ oil via the re-charge lines, you are asking for problems usually. Not only is it far too much oil to fill via those lines, but you potentially could run the risk of damaging your compressor when you first fire it up that way (since there may be no oil in the compressor yet).

Ray

 

Thanks for the reply Ray. I purchase PAG-100 previously as I read on a thread that that was the correct oil. I will go with the PGA 150 now. I have filled systems before and I have a Harbor Freight vacuum pump that I use. I have a 20 pound tank of 134a which I will weigh out before and wile filling the system, so I put in the correct amount. What do you suggest on the qty of oil? As I mentioned, I flushed out some of it from the line from the compressor to the dryer at the front. The system calls for 9 oz. I will have 3 in the compressor. Maybe 3 more in the line?

 

Yeah the HF setup should work fine. As I remember, the gauges on their manifold set are pretty nice.

If the system is totally dry, then the manual calls for just slightly under 9 oz. If there is some residual oil left in the system, it's very hard to say. Did the shop that rebuilt the compressor measure if there was any oil inside it and let you know how much? If they extracted 3 oz of oil then put 3 oz back in.

Usually in cases like this, you have to carefully measure how much oil comes out while working, then put that much back in. Kind of like with transmission stuff - unless you replace every single line and drain the torque converter, etc. then you have to basically measure what comes out and put that much back in kinda routine.

Mostly on want to be careful not to over fill the system with oil. Running a touch less oil generally isn't gonna hurt too much, so long as there is oil in the system. Naturally, you want the exact amount that Ferrari shows, but sometimes that can be hard to get back to exactly when some of the components are still in the car and may still have some level of oil inside them.

Ray

 

Adding to this thread, rather than starting a new one -

PAG oil has been leaking from my AC condenser outlet fitting behind the front bumper. I have no idea how much has come out. It's easy for me to wipe it down, and it's not like there are pools of leaked fluid underneath it. Anyway, I will be replacing the condenser soon. @RayJohns how much PAG-150 do you recommend I top off with? Should I drain the system entirely, like from the compressor, and just refill with the ~9oz?

Thanks
Connor

 

Hard to say, if you don't know exactly how much has leaked out.

A lot of the oil should remain in the compressor I believe. In most cases, you wanna start with a compressor that is new or rebuilt, so you know it has zero oil in it and then go from there. If you are just shooting in the dark, I'd say maybe add 20% of what the total grams is and just figure some oil is better than no oil in there.

Ray