2001 Cherokee, it came with out an ac compressor. In it's place is a steel plate with a pulley that takes the place of the ac pulley. The lines have been left uncapped for how long, but seeing as it has lines I'm assuming it did at one time have ac and for some reason the ac compressor was removed.

The question is, I currently have the belt off because I'm in the midst of replacing the steering pump. I have an ac compressor I bought, remanufactured. But I think it'd be a bad idea to simply hook up the lines considering who knows what kind of dirt and moisture is in there. Can I install the compressor but leave the lines unhooked till I bring it to a shop to clean the lines Monday? Should I remove the screw currently holding pressure within the compressor before I drive with it unhooked?

It's certainly not hard to take the belt off again, but it certainly doesn't hurt to ask. And I failed to find a similar situation elsewhere on here or on google. Any suggestions are awesome!

 

Yes, the compressor can be installed without the hoses connected. The accumulator/dryer along with the liquid line/orifice tube should be replaced with new. If u don't, u take the chance of ruining the new compressor. The evaporator, condenser and hose manifold must be cleaned internally with a/c flush and blown dry with compressed air. Any oil in the new compressor should be drained prior to installing the compressor. The correct amount of PAG oil should be added to the system prior to a vacuum being pulled and the correct amount of refrigerant being added.

 

Alright awesome, thanks. Should I plug the ac unit in or should I leave the electrical plug unplugged as well?

 

And by remove the oil from the compressor, do you mean prior to installing it with out the lines? Or should I leave the oil in until I plan on connecting the lines?

 

Yes, turn the compressor up side down and drain any oil prior to bolting the compressor down.

From what I've read, r134a systems are very finicky regarding the total amount of oil in the system. A little too much oil and cooling performance suffers, a little short on oil and the compressor suffers. U need to determine the amount of oil the factory states for a 2001 XJ a/c system. Measure out whatever that amount is and add 1/2 to the new accumulator/dryer and the other 1/2 to the empty compressor at the suction/discharge ports prior to connecting the suction/discharge lines to the compressor. Then button up all the remaining connections and take your XJ to a a/c pro and have them pull/hold a vacuum/add the factory spec amount of refrigerant.

This is the way we did our a/c overhaul and still have low/mid 30s at the center vents almost 4 years later.

 

Just to add to what djb383 said about changing out the accumulator/dryer. If you read the warranty card if you don't replace them you void the warranty. So if you do crap out your new compressor because you didn't change them you will end up having to by a new one.

 

The Evaporator and Condenser should be flushed prior to hooking up the new Accumulator and Liquid Line/Fixed Orifice, and Suction/Discharge hoses. Use new o-rings on any existing couplings. Prelube all o-rings with PAG100 oil prior to assembly.

The new Compressor gets 4 ounces of PAG100 added to it prior to installation. Oil is added through the Suction port on top of the Compressor. The paperwork that came with the rebuilt Compressor should tell you about preping the Compressor. The Accumulator gets 4 ounces of PAG100 added to it prior to installation.

 

if it is a new compressor leave the oil in the compressor it's new oil any way. measure oil from the receiver/drier and let the shop know how much oil came out of it because the oil can be added when the refrigerant is added . to be honest with you though, in order to keep moisture contamination to a minimum you should leave the caps on the compressor and the drier and allow the shop to hook them up when they are ready to put vacuum on the system. you may want to ask them to leave it on a vacuum for at least an hour to boil off any residual moisture in the rest of the system if it's been open for god knows how long. good luck.

 

Do u know how much oil is in the compressor? It either needs to be drained and measured and re-added to the compressor or drained. If it's re-added to the compressor, that amount needs to be subtracted from the system total. Again, the correct/precise amount of oil in the system is extremely important to max cooling and proper compressor lubrication.

 

My rebuilt compressor came with no oil in it, other than preservitive oil, so I would think the OP's compressor came the same way. If it has oil it I would dump it and add fresh PAG100 oil (4 ounces) because it may be contaminated with moisture.

 

What CCKen said. Drain the new/rebuilt compressor, start at zero oil and measure out the amount of oil called for by factory spec. IIRC, we poured out something like 2+ ozs out of of our new compressor out of the box. Based on that, our system would have been over filled 20-25% if we hadn't drained the new compressor. Again, everything I read said too much oil would reduce cooling performance