Does anyone have a factory service manual or know off hand the R134 refrigerant and associated lubricant capacity for a 1996 SL? I just replaced a damaged condenser on my son's SL, but did not disrupt anything else in the system. There was clearly oil still left in the system so I'm guessing I will now need to add about 20-30% of the stated value to replace what was in the condenser or lost to the leak and bring it back to proper level.
At this point I am planning to draw down a vacuum and leave it overnight to make sure the system is no longer leaking. I then plan to add the full R134 load and about 25% of the rated oil needed.
Can anyone supply the capacity of the system and/or any suggestions on the amount of oil to add? Thanks in advance.
No factory manual? The manual contains a lot of information that I'm not going to cover here. To much to cover...
-------------- The following is for Bobs car in Bobs case, anyone else attempting to use this information in a different situation may find themselves in trouble.
-------------- I take it you have a 134a gage set? Good thing to have. Since you're starting with no refrigerant I dont mind tell you what needs to be done in the repair part.
Did you also replace the receiver drier? It ought to be replaced as well...
-You need to add 0.75-1.00 oz of oil for the condenser and 1 oz more for the Receiver Drier. (system holds 6 ozs max.)
-From the manual: "Upon replacement of a component which caused a large refrigerant leak, add 90 ml (3 oz) of new PAG compressor oil plus the required amount of oil for the particular component, as outlined previously." -- "If the refrigerant charge is abruptly lost due to a large refrigerant leak, hose rupture or collision, approximately 90 ml (3 oz) of refrigerant oil will be carried out of the system suspended in the refrigerant. Any failure that caused an abrupt refrigerant discharge will cause this oil loss. Conditions that allow the refrigerant to seep or bleed off over time do not cause this oil loss."
-Lub o-rings and threads with 525 viscosity mineral oil. PAG will corrode fittings.
-Use Saturn PAG oil, free of moisture, for internal use. Sorry I dont have the part # or viscosity on hand. Saturn calls for something different from the rest of GM's fleet IIRC.
-"Add the oil directly to the replaced component if possible. If the oil cannot easily be added to the replaced part, add the oil to the compressor discharge port side hose"
-Make sure you do not use 134a with sealant or seal sweller. Will only ruin your system.
-Make sure you schrader valve caps still have good o-rings, they are the primary seals for the system.
Since the system holds 24 ounces its easy to throw off its efficiency with a slightly incorrect charge. I hope you know what you are doing from here Bob...
Thanks for the good info and caution. I have the pump, gauges and have charged R12 and R134 systems previously so understand the caution and the need to reclaim the refrigerant whenever possible. No, we do not have the FSM. I know we should and I do for my other vehicles, but this one was purchased used for my son and I never bothered since it has been so easy to work on and so reliable.
To keep the costs down, we are using a salvaged (junk yard) condenser. I purchased 2 new O-rings at the Saturn dealer and had sealed both of the fittings after removing the old condenser to minimize water vapor entry into the system. Based on the actions taken, I'm going to try to get away with not replacing the receiver/drier and see how it goes.
For others who may be reading this thread in the future, to summarize, the capacity of the system is:
If the salvaged condenser has been exposed to the elements for any length of time, I'd flush it. You can buy a flush kit from any auto parts store. You don't know what kind of crap was in there...sealants/incompatible oil/water/etc. Given the amount of labor involved, I'm not sure I'd even waste time with a used part here, but that's water under the bridge. Re-using the old receiver/drier is a serious mistake. The desiccant inside will VERY quickly become contaminated with water vapor even if exposed to the outside air for short periods of time. I'd stop now, replace that, then keep going. You'll be kicking yourself later when you've got to do the job again.
I'm guessing you don't have any way to exactly measure the amount of R134a you're adding to the system. As a rule of thumb, follow this chart I've linked to below. At a given ambient temperature, with the A/C system on high, your pressure readings should be in the range of those on the chart:
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There is also a wealth of other information for the DIYer there. Working around an auto A/C system can be quite dangerous if you're not familiar with procedures as the high side of the system is under a LOT of pressure. Be careful.
Agreed on flushing. No telling what was in the system of that old condenser. Also GM says after X number of years to replace the drier during servicing. Yours is well past that age.
I think with the zexel pump the system holds 6 ounces.
They also have a informative forum.
All I can say is read read read, ask questions, and read some more.
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