dzywicki

I am stumped on replacing the low side AC valve core. I needed to replace the condenser. While I was vacuuming the system, the low side AC valve core started leaking when I removed the vacuum valve. Looked all over the interwebs and it seemed like a pretty simple replacement. A regular valve core removal tool won't work so I found one for larger valve cores. Turned that really hard and the valve core was not budging. Next step was to make a better one out of a bolt. I cut a notch in a bolt so I could get a socket on the top. After applying way more force than would be possible to hold the valve in in, the homemade remover started bending (see images). Just for grins, I decided to try the high side valve. that one came right out.
This is the original AC hose assembly. I have seen some articles about the low side valve being nonservicable, meaning the entire hose assembly must be replaced. Is this really the case. If it's not, then I must really be doing something wrong here.
Pictures are ont eh tool I bought, tool I made and the low side port. The kit I bought says it's for a 99 Cherokee and includes several small valve cores, a few larger size, a complete service valve (no idea where that would go) and some caps.

Has anyone figured out how to replace the low side AC valve core on late model XJs?

dzywicki

Went to the pick a part this morning to see if I could get a hose where the valves were removable. Found 2 2000 XJs where the valves came right out. Took the hose, replaced the valves (already had the replacements) installed the hose and started the vacuum. I looked at the old one closer once I got it out. It looks like a normal valve. Must be frozen in there somehow. Going to vacuum down the system and then charge it tonight or tomorrow and should be good to go from there. I did have to change the high side pressure sensor. On the 2000, it was a different connector. Luckily the old one came right off and went onto the replacement hose.

Turbo X_J

Did it have a tight fitting cap w/ o-ring on it?

dzywicki

The cap has been missing for awhile. The evap core and compressor was replaced by the local Jeep dealer 5-6 years ago (before I really took over heavy maintenance). But I don't believe there would have ever bene a reason for anyone to do something to that valve. It was my wife's car and it probably had the AC checked a few times over the life of us owning it.
We have owned it since new and I make sure I put everything back as I found it. I have never been this far into an AC system before but this system has certainly not been abused. If you look a the pics, I would say this is pretty typical for a 17 year old vehicle with the original AC system. Just out of curiosity, I'll probably cut the whole stem off tomorrow and look at the back side. I have been doing pretty heavy maintenance on vehicles for quite awhile but have not run into something as odd as this. I can't imagine someone putting thread lock on something like that.

Turbo X_J

The cap keeps out water/dirt.

Aluminum tube + steel valve + a little moisture = it's toast.

dzywicki

The high side didn't have a cap on it either. Not sure if it was the dealer or one of the other places my wife had taken it to in the past. That valve came right out. I put some PB blaster on/in it today just to see if that would do something. Was going to let it sit overnight. May hit it with the propane torch tomorrow if I get really bored. Will definitely cut it off and have a look for my sanity.
The valve kit I got has replacement valves and caps so the new caps will definitely go on.

dzywicki

Got everything done today. Vacuumed for awhile and then put in 20oz of r134. I had replaced the accumulator and condenser so added about 4oz PAG 100 oil before vacumming. Had high side pressure right at 225 and low side right at 30 so pretty much right on. Air out of the center vent was right about 32 degrees. So I think I'm good to go on AC now. Even put the replacement caps on.