Volvo 850 How to add oil to new a/c compressor

[JimBee]

Not a new compressor, actually, but used and has been out of a car for a year. I'm sure there's no oil in it because its ports have been open (although plugged with a paper towel and baggie over one with the hose attached), and it has been carried and stored at different angles.

I'm also installing a new, yes new, accumulator, so that doesn't have any oil in it either.

The Zexel compressor has a badge that specifies how much oil is needed, but it's not clear how to get oil into the system. I'm concerned about running the compressor at all with oil not directly into the chambers so everything is lubed from the beginning.

Expert advice appreciated!

[abscate]

I think these specs apply to the 1999 and earlier cars, per Alldata

Total PAG capacity listed as 200cc, so it looks like the compressor gets it all. Note the compressor should always get 70cc min per this document.

[cn90]

- PAG oil is need only at the compressor for lubrication, anywhere else (evap, dryer, hose etc.), it is just a nuisance (not needed).

- At factory, during a dry fill, they put in a total of: 90 + 50 + 200 + 20 + 20 = 380 cc (or 12.6 oz) of PAG oil.

- Then during the life of the car, when you turn the AC on, oil is distributed throughout the system as shown by abscate above.

- In some cases, PAG oil leaks out with time via the front seal or leaky O-rings, when you remove the old compressor, you may not see much oil coming out even if you drain it. But when installing new compressor, you should put in about 200cc (around 6-7 oz or so) in the new compressor.

PS: the compressor you buy is old and may be contaminated, so flush it twice before installing: add some PAG oil, spin the shaft around, drain it. Repeat the process etc. During the last fill, add 200 cc. Add oil via the "LOW" side, then spin the shaft.

Generic video below:

[JimBee]

Thanks, gentlemen of the wrench, this is helpful.
Just to confirm, so i don't need to portion some oil into the new dryer, just pour the whole 200 cc's into one of the ports? Won't some spill out during installation, connecting up the lines?

If I drain and refill, which seems like a good idea, I'll want to be careful to measure the amount that drains and refill only the difference between that and 200?

Is the low side the line with the flex hose?

BTW: the video is helpful, thanks!

Re the failed compressor that locked up: looking into the ports, it appears free of any debris. Today I popped off the end caps and discovered there are actually 6 bores with pistons—3 at each end. Those bores were as smooth as glass, no sign of damage. I didn't go into the middle of it where the wobble plate lives, there must be a bearing or bushing in there that froze up. There was a little residual oil inside both front and back, but very little, maybe a couple of dropperfuls.

In the replacement compressor I installed a new bearing in the pulley and reset the clutch gap to .43 mm, which is about in the middle of the recommended range.

I haven't tried to break open the garter spring connectors at the firewall, which I kind of wanted to, partly so I could get easier access to the orifice tube and change that out, while also flushing everything. Since there doesn't seem to be any debris in the failed compressor, and I'm installing a new dryer, now I'm thinking I don't want to mess with other parts of the system to flush, etc.

Comments?

[abscate]

You want the clutch gap to be on the tight side. It's a wear item, it will only get bigger.

The low side is the side coming from the evaporator in the car, the high side will go directly to the condenser to get cooled. I think they are both flex pipes

Will try to link pix.

[cn90]

How many miles when your AC compressor seized?
Did the seizure burn the serp belt?

[JimBee]

I assume the compressor that seized was original, by its appearance and all the fittings, etc. Miles on it would be around 180k. The car was stationary and at a high idle when I smelled smoke and immediately shut it down. The smoke was from the serp belt. It's not visibly damaged, but I'll replace it anyway.

After it cooled, I could turn the clutch with a screwdriver with some moderate effort, but it was obviously binding, as though a bearing had seized. Like I wrote above I pulled the end caps to see the bores, everything is laboratory clean on both ends, bores are smooth, piston tops are clean. Each end has what appears to be a "cylinder head" and gasket, which are all clean. So I'm not worried about fragments from something grinding up inside.

I suspect it was low on oil. Why? I had a local indy replace the dryer and recharge the system for me. When I picked up the car, just after I started the engine and moved 3 feet the dryer coupling blew apart explosively. That was the new dryer. The tech was standing right there. There was a mess of refrigerant and oil in that area. At that point there was no way to know how much oil was in the system without starting completely over. What might have happened is when they redid the coupling and recharged the system with the machine, there was not enough oil. Or driving the car back into the shop to put it back together with the system open. Did they vacuum it again? I don't know.

I had maybe 3 months of use on it after that when it seized.
After the indy thing, the car had sat all winter and the system had lost some pressure. I was adding some refrigerant when it locked up. I had topped up the R134 previously on this car and another 850, I thought successfully, but maybe I got too much into the system this time, or something. I've read a couple of competing theories on how to top up, one of which indicated that it's easy to do it wrong, causing damage. I'm just guessing. Maybe it died from old age :\

[abscate]

There's little better than recovering, evacuating, testing and then charging by mass

If you do a lot of AC work you can set it up by pressure but most don't have the right equipment to do that

[JimBee]

In the neighborhood there's a first class repair shop, trusted and highly rated, great people. His complex is called "Amigo" and he means it. The owner is extremely knowledgeable. I went there today and ran this by him and he basically told me the same thing commenters have been saying—and that video linked by cn90 showed. Put the 200 cc / 6.4 oz. (pag 46, I guess) right into the compressor before installing it. The oil will apparently sit in the bottom of the compressor so it won't spill out.

Flush it? Why not. This is the replacement and while looking into the open ports it looks clean, I didn't take it apart to examine it further, so running some fresh oil through it won't hurt. Then I will want to hold it vertically like the guy in the video shows, turn the clutch plate, then empty out all the oil (that will come out) into something that shows the volume so I can be sure of how much, if any is left inside—then fill with amount needed to 200. Don't worry about putting any in other components, which probably still have a little in them (I'm installing a new dryer that won't have any in it). The local guy said that's how they begin when installing a new compressor. Then when the machine installs fresh refrigerant a little more oil is usually added.

One question referring to the video: The demonstrator puts in the oil then holds the compressor vertically with the open ports up and turns it over with the clutch appearing to burp it. But if I do that, there will be oil in the cylinders which is likely to leak out when the compressor is held horizontal for installation before the pipes are connected. So is the burping step necessary or even wise? Because if some oil does leak out during installation it won't be caught to be measured, then I'm back to needing to do it over. Maybe that's the flush step; it gets some lube on the cylinder walls and probably the wobble plate and internal bearings hopefully; then empty it out, measuring what comes out and fill accordingly to 200. Then install the compressor.

The other concern I have about the machine they use in shops is oil compatibility. In the info sheet abscate copied above, there is a stern warning not to mix oil types. So what happens when the machine in the repair shop doesn't have pag 46, but who knows what in it and that gets mixed with the right stuff?

[abscate]

Where are you Jim? Are you close enough to ship gauges and pump and do this yourself?

Running 5 cars, I found the Harbor Freight set paid for itself with the first AC job, now it's paid for itself 5x over