AC repair with crazy unexpected issues, please help!

[SClemons]

Good morning everyone! Once again, I am working on the 1998 TJ sport 4.0.
The air died, apparently from a hole in the accumulator. I ordered a compressor and an accumulator. It arrived, only for me to discover that the compressor on our TJ is not the same. Upon further research, I discovered that someone has switched everything on this jeep to a YJ AC system.
I have thoroughly inspected everything I can see under the dash and I don’t think they changed the evaporator. The dash does not look like it’s ever been out.
I have bought everything new for a 98 TJ
Compressor, condenser, accumulator and all new lines.
I know nothing about AC!
I read the instructions that came with the compressor about removing the oil and re-adding the oil. I have read about vacuum testing and I’m not going to lie, my mind is boggled.
I’m better at hands-on learning and reading
My question is with everything new except for the evaporator sitting here, how should I proceed step-by-step to finish this job? I have not installed anything yet because I’m not sure how to proceed.

 

[macleanflood]

Got a vacuum pump and gauges?

See if the system will hold vacuum for an hour with the pump running, Then try another hour without the pump running.

-Mac

 

[KennethS]

Drain the oil from the compressor and each of the other removed components, so that you can measure how much oil came out of the old parts. That is the amount of fresh oil to add after the new parts are installed.

Assemble all your new parts, and use new o-rings on everything.
Draw a vacuum as said above to ensure there are no leaks.
Add the proper amount of refrigerant to the system. You can use a scale to weigh a 30 pound tank, or use the appropriate number of 12-14 ounce cans, or bring it to a shop and let them add the refrigerant for you.

 

[06lj]

I recently replaced my entire A/C system. I was apprehensive but had no issues. If you have basic mechanical skills it shouldn't be a challenge. Installation of the parts is straightforward. If your replacing everything else I would install a new evaporator. My Jeep is an 06 and the evaporator was half clogged with dirt and debris. I would also recommend picking up some Nylog gasket sealant as it lubricates the o-rings and acts as a thread sealant. Be very attentive to ensuring all of the o-rings seat well, especially the evaporator lines at the firewall. Fill the system with the compressor manufacturers recomended oil. Buy or rent a vacuum pump and guage set. Pull a vacuum to check for large leaks. If you can maintain a good vacuum then use the pump to remove any moisture. Once you are ready to fill weigh your refrigerant, purge your refrigerant line and add the correct amount.
There are several videos on YouTube that have step by step demonstrations of the entire process of recharging the system.