2000 Cherokee Sport won’t hold A/C Charge at all??
 

The AC system isn't really that complex on these Jeeps. I used to take my Jeeps to an AC place, but got tired of paying someone else after awhile. If you invest in a few tools, you can do everything yourself.

1. quick disconnect
This worked for me:https://www.harborfreight.com/3-piec...set-38732.html
2. Vacuum pump:
If you have a decent compressor - https://www.harborfreight.com/air-va...ors-96677.html
If you don't have a decent compressor - https://www.harborfreight.com/quickv...index/id/10270
3. AC Gauge set
https://www.harborfreight.com/ac-r13...set-60806.html

And you will also need a seal and oring kit:
https://www.rockauto.com/en/moreinfo...363384&jsn=403

And a receiver drier:
https://www.rockauto.com/en/moreinfo...363384&jsn=410

I'm assuming you don't need a compressor or evap core. Comopressor is easy with the above tools, evap core is painful any way you look at it.

Hook up the gauges to the low and high side ports. USe the vacuum/compressor or vacuum pump to pull a vacuum. It should pull down to -30 hg. Once you get it there, close everything and see if it stays. If the pressure rise back to 0, you have a leak somewhere and will have to dismantle the system
There are five line connects in the system. 2 on the firewall, 1 on the receiver drier and 2 to the condenser. You will have to use the quick disconnect tool to wedge into the line connect and then turn, push and pull until they release. It can be a bugger to get them released. Just keep twisting and pushing pulling and they will eventually come off.
Once you get those all released, you can replace the orings and springs. Get some PAG 100 oil to coat the new orings. Replace the orrings, replace the receiver drier and get it back together. If you are inclined, you can pull the connector off of the compressor and repalce that seal and o ring too.
You can use this chart to determine R134A amount: http://www.techchoiceparts.com/refri...apacities/jeep

Once you get it back together, hook up the vacuum pump again and pull the vacuum. If it holds, let it sit overnight to verify it's completely sealed. When I use the cmpressor driven one, I fill my compressor and then let it pull until the compressor kicks on again. then I close it, let the compressor catch up and repeat for 30 minutes or so.
Once you get a good vacuum, then you can refill the system with R143a as specified in that chart. I have a little scale I use for home brewing that gets me to the right amount. you will definitely want a gauge set to ensure everything is correct.

This is the chart I use. The high side will depend on the ambient temp: http://rechargeac.com/how-to/ac-system-pressure-chart

All in all, if you invest in the tools and learn it, you will be ahead of even 1 visit to the AC place.

I have used this method on 3 different Jeeps and the AC systems have been working perfect for years. Compressor went out on one and was so nice to be able to do it all myself. There are some youtube videos on capturing 134 if it's in the system. The times I had to do work, there was nothing in the system to recycle.

Good luck