Hi all,
Finally had time to replace the leaky a/c condenser (1994 XJS. 4.0), and the dryer since, well, why not, and it appears to be holding the vacuum well. After doing some searching, there are varying opinions on how much PAG-46 oil to add to the system. On a post dated May 2013 (Recharging PAG Oil along with AC Condenser & Drier), a responder indicated just .5 oz is needed. Should I go with that advice?

 

From the manual, "Typically [2.7 oz] may be drained from the original compressor and [1.0 oz] found in the oil separator; if these quantities are added together - [2.7oz + 1.0oz = 3.7oz]; then this is the amount of fresh PAG that must be put into the new compressor prior to fitting. Please note that this discrepancy between this figure and the nominal capacity of [4.5 oz] is caused by normally unrecoverable oil being trapped in components such as the receiver/drier or evaporator. The previous statements are only valid if there is NO evidence of an oil leak from the system. If oil has been lost and the fault attended to, then the compressor, whether original or replacement, should be filled with the specified quantity."

Doesn't help much, but 0.5 oz doesn't sound crazy. I certainly wouldn't put any more than that in.

 

I did mine recently too. I flushed out the evap and condensor with an AC flush to remove the old oil. Then flushed carefully with air. The compressor has a certain amount in it (3oz rings a bell), so I added just a little more to what ever the spec was I read in the manual.

 

Thank you so much for both replies! After pulling a vacuum last night, I checked it today to see how it held. It appears to have lost one pound of pressure, so I'm assuming there is a small leak somewhere. I did reuse the same o-rings (dumb), so I'm replacing them. I also seem to recall seeing some oil around the a/c ports in the past, so I figured that I would replace the Schrader valves, but--surprise!--they are apparently can't be removed, so I've ordered a new set of high/low ports to replace them fully. Hopefully by Friday (after another night of holding a vacuum), I'll recharge it.
--Keith

 

yeah I forgot to mention to replace the orings too...do the expansion valve too...mine was missing the small oring for the tube connection...fun time if its the old style one.

 

And, you're right; if I'm in this deep, I may as well replace the expansion valve. Looks like the recharge will have to wait.