I haven't changed a compressor since the A6, R4 & York days but Mitchell says if changing compressor drain compressor out what came in it & put back correct amt. What that means? Who knows.
The new compressors dont have an oil sump like the old yorks, they get there oil as it flows through the system. There is a specific amount of 134a and a specific amount of oil for these systems to operate properly. By measuring and replacing the same amount of oil you can get pretty close to maintaining the correct lvls of oil.
Thank you to all for the advice. Stu, a special thanks for the advice and your website - that was what got me started on doing the repairs.
Here's the lessons learned:
1. Leave the DIY cans of R134a at the autoparts store. That $5 can may lead to the $500++ repairs like mine otherwise.
2. R134a is not something to mess with. Have your system drained PROFESSIONALLY before starting.
3. If you want to replace the orifice tube don't waste your time buying the $3.00 one. Buy the line with the orifice tube already in it. If you replace the orifice tube you should replace the accumulator as well. Total for both is around $100. You might be one of the lucky few that can actually get the old orifice tube out of the liquid line. If you do, let me know your secret.
4. Get a pro to sniff out/dye trace your leak if you have one. Don't waste your time or money on the leak fix chemicals that are on the shelf next to the DIY charge kits. The Jeep system is not built to operate with that stuff in it. Think tiny orifice in that tube and you'll understand why.
5. If you gotta get parts and want a good price check out Jeepair.com. They did me right as well as many others on this board.
6. If you try to scrimp a few bucks here and there you'll probably end up spending them in the end. IOW - don't waste your time on a reman, junkyard, or hand-me-down compressor or other parts. Do it right or don't do it.
7. Cleanliness is more than a virtue - when it comes to your AC system it is an absolute requirement. Keep the gunk out of the lines and connections.
8. On the 4.0 TJ you really do have to move the power steering pump (not disconnect - just move) or else you won't be able to get to the bolts on the compressor.
9. Buy some PAG oil and replacement o-ring kit - you'll need them.
In the end I replaced the compressor, the condenser, the liquid line w/orfice tube and the accumulator.
Total cost was $600 for all parts, a purge, a flush, a vacuum draw, and a recharge.
She's blowing cold now and I pray it stays that way. If not then I'll be doing an evap + accumulator changeout too. (Ugh.)