Furthermore, when I seek out other sources for this info, there's not much first of all, but I found this site: http://www.compressortech.co.uk/refrigerant-weight.php

Using the search bar on that site to narrow down to "grand cherokee" I see both qty's, the one I found for a total of 130mL as well as the larger 220 mL per that link to the post, but this site associates that qty with only the 3.1 Diesel option.

I'm going to have to assume my FSM is correct for my application, because it's completely plausible that this other post (where the user says they downloaded it) happened to download for the wrong engine.

But if anyone has other thoughts, please share them here. There really seems to be a remarkable variance in available values for this which is most troubling.

EDIT: One last note, I also see in my searching that there's some confusion about refrigerant capacity as well, specifically whether or not 24 oz or 27 oz. This same site also shows refrigerant capacity, but no mention of unit of measure, so I'm assuming it's in grams (as doing a conversion of those values in grams to oz yields approximate expectations). But I see that this delineation between 27 and 24 comes in when 2005+ year models are looked at. So I'm feeling pretty good that I've uncovered that there's a lot of mismatched info out there and that what I found verifies I'm on the right track.

 

For the WJ which was manufactured from 1999 to 2004, the accumulator and evaporator changed beginning with the 2002 model year, and the condenser changed mid-production in approximately March 2003. I believe all that really changed on the evaporator was a different connection type - the size couldn't have changed much if any.

Anyway, I'm not sure how much overall system oil capacity might have been altered by those component updates, but I guess it's a possibility. It might explain why there's a discrepancy from various sources when looking up the info.

I've seen anywhere from a total of 5.x to 8 ounces so I'm not sure what to believe. I tend to trust the FSM but it's not 100% infallible either. Of course, too much is just as bad as too little, and even though there's an acceptable range, there must be a theoretical exact amount for optimum cooling and compressor longevity. I don't know what that number is, and I've never been exactly sure how much oil was already in the system, so I tend to err on the side of slightly too much rather than too little.

Because of uncertainty about all of that, I bought an oil injector that lets you add oil to a pressurized system. After a component change, I've used that before to up the amount in 1/2-to-1-ounce increments.

Also, I've seen anywhere from 24 to 26 ounces of refrigerant listed as correct, but I've found through trial and error that 24 ounces tends to work best for me. Supposedly, it's better to charge based on pressures and ambient temperature rather than sticking to strict stated capacity (within reason).

 

Re:

Ok, I'm officially confused. I thought I was good to go based on the info I found in my FSM:
View attachment 4242070
But when looking for some more info, I came across this post which shows a screenshot similar to mine but with completely different numbers!

https://www.jeepforum.com/threads/pag-100-oil-to-add-for-each-a-c-part-replaced.3791098/#post-35591474

Is there really that much difference in PAG capacities between a 99 (the WJ in that post) and my 04?

And while I'm here, I'll mention that I'm getting ready to replace every AC component, except the evaporator, so I feel as though getting the right numbers is critical given how drastically different these capacities are between two screenshots.

This is from a 2004 Service Manual for the WJ:

REFRIGERANT OIL
DESCRIPTION
The refrigerant oil used in R-134a refrigerant systems
is a synthetic-based, PolyAlkylene Glycol (PAG),
wax-free lubricant. Mineral-based R-12 refrigerant
oils are not compatible with PAG oils, and should
never be introduced to an R-134a refrigerant system.
There are different PAG oils available, and each
contains a different additive package. The 10PA17
compressor used in this vehicle is designed to use an
ND8 PAG refrigerant oil. Use only refrigerant oil of
this same type to service the refrigerant system.

STANDARD PROCEDURE - REFRIGERANT OIL
LEVEL
When an air conditioning system is assembled at
the factory, all components except the compressor are
refrigerant oil free. After the refrigerant system has
been charged and operated, the refrigerant oil in the
compressor is dispersed throughout the refrigerant
system. The accumulator, evaporator, condenser, and
compressor will each retain a significant amount of
the needed refrigerant oil.
It is important to have the correct amount of oil in
the refrigerant system. This ensures proper lubrication
of the compressor. Too little oil will result in
damage to the compressor. Too much oil will reduce
the cooling capacity of the air conditioning system.
It will not be necessary to check the oil level in the
compressor or to add oil, unless there has been an oil
loss. An oil loss may occur due to a rupture or leak
from a refrigerant line, a connector fitting, a component,
or a component seal. If a leak occurs, add 30
milliliters (1 fluid ounce) of refrigerant oil to the
refrigerant system after the repair has been made.
Refrigerant oil loss will be evident at the leak point
by the presence of a wet, shiny surface around the
leak.
Refrigerant oil must be added when a accumulator,
evaporator coil, or condenser are replaced. See the
Refrigerant Oil Capacities chart. When a compressor
is replaced, the refrigerant oil must be drained from
the old compressor and measured. Drain all of the
refrigerant oil from the new compressor, then fill the
new compressor with the same amount of refrigerant
oil that was drained out of the old compressor.

----------------------------------------------------------------
The A/C Compressor I got for my 2003 WJ with the 4.0 liter engine is made by Denso and is Model Number: 471-0400. I don't know for sure weather or not the WJ's with the V8 engines have same compressor etc., but there is nothing in my 2004 SM that indicates there is any difference in the PAG Oil Capacities Chart.

I got a brand new A/C Compressor from Rock Auto and it included the A/C Compressor Clutch.

 

May I ask why you're replacing all those parts?

 

Prophylactic measure, it tends to be my way of doing things lol I actually ended up skipping on replacing the condenser as well, because my old compressor did not have any indication of any internal damage, so I have no reason to believe any compressor shrapnel would have made its way to the condenser. So I just replaced the compressor, TXV, and drier. The old compressor did have a leak, but I couldn't see it until after I removed it. On the bottom of the back plate there was some oil.

 

But…, are you seeing pictures?

I can’t…. 😔

 

Sorry you can't see them.
Yes, I can see them at the moment, but that has not always been the case in the last several days.

Also, FWIW, in this thread, there are only 2 photos and they are both just service manual charts for Refrigerant Oil Capacities for each component and the total for the whole system and they differ somewhat.
The one at the top of the page, (#1), for "A.C System" says 130 ml, (4.40 fl oz) and in the one I posted says: 170 ml (5.75 fl oz).