EEVEE

I was wondering where are common places for 99 jeep cherokee ac systems to leak at? I had a slow leak i know of and its at the low side fill port and when i take the cap off i hear a tiny hiss and a little bubble test it leaks just alittle bit. Would that cause my ac to start fading after like 3 months of use after pumping out and recharging my system? i figured the rubber seal on the cap would keep it in but id like others inputs on it. It does cycle for about 5 seconds then turns off and pops on right after at the compressor. Is that normal? Its been very muggy and hot outside and my ac doesnt seem as cold as it was when it was charged even when it was sweltering hot outside. So where are common places for it to leak besides the fill port and if the port is the major issue how can i tighten it without hitting the release button? would hate to redo the system all over again lol.

OldTires

The valve is probably bad. I had this happen on my high side hose, which was just 2 years old. Since the high side pushes out, I could feel pressure on my thumb if I put it over the high side valve port.

I had the system discharged and then I bought a $14 valve kit from Amazon and changed it myself.

Later did I find out that there a valve tools that allow you to change the valves without discharging the system. Crazy.

I would go to an AC shop and ask them to use their sniffer tool to find the leak and then fix it. And if it is the valves, they should be able to change it without discharging.

OldTires

These are the valve kit I bought. Well worth it as the kits at the parts stores around me didn't have the valves I needed. And the tool is great.

This is the type of tool that allows the valve change without discharging. Disclaimer here is I haven't used it so I don't know how well they work.

EEVEE

Holy crap! that tool is awesome! i may have to invest in it lol. If i do get it ill report back and tell how it went. But they will let you use their sniffer for free? i just want to check to see where its at first before i go replacing random parts.... Then again those valves are old. been in a system with no charge at all for a good few years and sure the heat got to them so maybe it is just the valves. i tightened them before when it wasnt charged a long time ago and the hissing stopped it was only recently i got the system all back to working condition. The hissing i mentioned is barely audible you can only hear it when the jeep is off but i carefully put some bubble liquid over the port without dripping it *very tedious* and it popped i didnt get a chance to see if it was blowing a bubble or sucked it in. My dad said if the valve is good the bubble will stay there till you pop it but if it pops there is a leak.

EEVEE

May have found the obvious leak lol. So i go poking around my engine bay to check the fluid levels as per usual. And im looking at my service ports for my ac, So i open the low side up and a little itty bitty hiss like usual but i went to open the high side cap and holy mother of leaks. I opened the high side up and oh theres the leak when its literally bubbling and hissing like someone poked a hole in their tire with a nail. So im gonna change the valve cores out and hopefully that is the issue. I thought the caps would keep the leaks sealed i guess not.

OldTires

How old are the hoses? If they are old, I would change them. Of course it turns into a more expensive job and time consuming. I guess it doesn't hurt to try the easier fix first.

Don't be surprised if another old part springs a leak or malfunctions when you get the system running.

Good luck.