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ZJ now has AC!

PostPosted: Thu Jun 19, 2014 11:21 am
by pfarber
Yesterday was "fix the damn AC in the jeep" day. I had finally gotten all the proper parts and rigged up a fitting to allow the generic vacuum pump to hook into the HF R134a gauges.

It was obvious that the leak was from one of the accumulator lines.. the oil residue was not hard to miss... plus the previous owner must have tried every magical goo you could dump into the AC system to fix it.. dye, sealers you name it. All it really needed was a new $30 part. I ended up replacing every line because the parts were cheap and if there was another leak I didn't want to piss away $60 in refrigerant for a $20 part.

Since my system was empty the process was pretty simple. I used the $5 plastic HF AC decouplers and was very happy with them. The larger metal ones would have never fit down where the condenser fittings were. So pro tip... get the $5 set and if you never need them consider them spares.. but they work fine for the once or twice you may need to use them.

Took a 5 minute draw on the system to see if it held vacuum (30 minutes later the gauge was still pegged at 0) so all my lines and seals were good.

Put the can tap on the can of R134a, open the low side and let the system suck in the freon. I did use a pot of hot water to help move the gas. After the first can I started the car so the system would pull in the rest of the charge. Second can was warmed up by allowing the radiator fan to blow hot air across it. About half way through the second can the compressor clutch finally stopped cycling and stayed on... the AC in the cabin was 45F. My ZJ takes 28oz of R134a, but I could not find a combination of cans that added up to 28oz exactly. Walmart has a special 3 12oz cans for $23 (that's a great deal) so I basically guessed at about 1/3rd of the last can. The low side stayed at about 30psi and the high side was 240psi. Good to go!

All in all I spent about $215 to basically replace every line, evacuate and recharge the system. Now I own an R134a gauge set and vacuum pump (which I will also use in my print shop so that's not a huge deal... pump was only $67).

I would rate this job at about 4 CCKW tires out of 11. The only part that you will not be able to do is recover any refrigerant if the system has a partial charge.. the machine to do that is several thousand dollars... but everything I read leads me to believe that a garage would do it for free as long as they get to keep the refrigerant.... so if that's true no big deal.. but I don't know it that's something that shops would do for free.

Here you can see the new lines... they are the clean parts.

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I didn't take many pics, but this is one I took while I evacuated the system. Most web sites say to draw the vacuum for up to an hour(!). The ZJ service manual says 20 minutes. I did the 20 minutes.

I would STRONGLY recommend that you get your cars service manual as a lot of the information on the web misses a LOT of critical information. Like adding oil, charge capacity and charts to show pressure vs temp.