hmmm......did a smoke test and didn't see any smoke. I then tried pressurizing the the system from my compressor. Had it up to ~60 PSI and didn't hear any leaks. I am starting to suspect my really old robinair gauges. When I was vacuuming the system, thevacuum woudl drop in half as soon as I opened the high side valve. I took apart the valves and didn't see anything obvious. This gauge set has to be at least 50 years old. Sadly, the rebuild kits are discontinued. Grok recommended a lichamp set that does R134 and R1234yaf. $90. Sold.

 

I thought grok was only good for **** these days.

 

I use all the major LLMs and run an uncensored local one. Grok is by far the least censored LLM. Claude and chatGPT seem to get more censored on a regular basis (in my opinion).

 

Been following this as brings back memories when I did mine. For leaks only issue I had was found out for some reason if I opened up my Mastercool all the way it would bend the Schrader valve core pin...live and learn I guess. I did however replace everything but the condenser also used .Nylog on the threads.

 

Well dang. New guages are really nice but still having a leak. Will check the schrader valves @country2 . Super weird that it will hold the vaccum at -29 with the pump going. Close up the valves, seal up the pump line, open it back up and it loses vacuum. Took the evap core out of the equation and got same results. Of course worked great before I did the heater core. It's gotta be something stupid (besides me).

 

F it. Ordered everything except evap core and compressor. Spent ~8 hours on the AC already. Done with it.

 

Not to insult your intelligence, but did you lube all the o-rings before you put the A/C system back together? Perhaps one isn't seated properly, so the vacuum allows air to sneak by, but positive pressure seals the o-ring.

 

Definitely lubed them with PAG oil. I even pulled everything apart and relubed the orings. I've done several AC systems and did this one and on my 98 XJ and never had this problem. Parts are supposed to be here Friday/saturday. May do some additional diagnostics prior. Super annoying.

 

Well son of *****. ****. Replaced the parts and was still having a problem. The replacement parts came with nice plastic caps. I tested each section and then finally got to the point where the evap core was not in the system and all was good. Then did another smoke test and got lots of smoke coming from the dash.I swear it was ok before I started my troubleshooting. It took a lot of effort to get the lines disconencted and then I did that a few times while troubleshooting. New evap core on the way and then do it all again. I had decided to not repalce the evap core since this should have been an OEM one from 15 o so years ago. Should have just replaced it. Never want to go back into the heater box again. May order a new blower motor too.

 

I really don't want to spend another weekend in the garage. Got the new evap core and decided to get a new blower motor. All of the studs in the heater box held tight so the nuts came out fairly easily. I pit some JB Weld plastic on them when I put them back. Going to wire wheel them all before I put it back in as some were a little difficult and fought to the end. When I lose my software job to AI, at least I can fall back to being a professional XJ heater box remover. Had it out in just under 2 hours. Another hour to replace the evap core and blower motor and tighten back up to go in.
Did a smoke test on the evap core and it was definteiyl leaking. I thought it would have been wher eteh tube goes to the body, but it was inside of the body where the red square is in the picture.

 

Glad to see you may of solved it. I dreaded doing mine and hopefully will never have to do another one. I did go ahead and replace the heater core while I head it out.

 

My OE evap core looked perfect, including the moisture trap foam sheet across the front of it. So I decided to reinstall it. Crossing my fingers it lasts a long time.

 

Got everything back together yesterday and did the final work today. Was holding a vacuum last night. Freaked out today on why it wasn't. Heard a hissing and it turned out to be the pressure sensor on t the drier/accumulator. Somehow the oring was missing. Got that fixed and was good to go. Added the PAG oil and charged it up. Was cold, but not ice cold. Of course my temp sensor gun was not working. Let it sit for a few hours. Checked everything again and all seems well. Hope it stays that way. Will double check pressures tomorrow. It was just over 60 today so on the very low end of all the pressure charts. Supposed to be closer to 70 tomorrow. The only thing I somehow misplaced was the line securing clip from the liquid line to the evap core. No idea where that went.
The compressor comes on and stays on so happy with that.

 

Got everything done. Seeing 55 at the vent. My 98 gives my mid 40s at the vent. Used a digital scale to get 20oz of r134a. 7 oz PAG 100 since I replaced condensor, drier and evap core. Still need to find a line clip. The old one disappeared somewhere.