Michael Belliveau

Hello all, I am going to replace my AC compressor because it's starting to rattle a pretty good amount when it turns on and last time that happened it seized up shortly after so I just want to do some preventative maintenance. I'm going to replace the compressor, condenser, receiver drier/ and expansion valve. I plan on pulling vacuum for 40min to make sure there are no leaks and get all the moisture out and then taking it in to get the correct amount of r134 and oil. My concern is the oil level, are the expensive robots at auto shops able to measure exact how much oil is in the system and add more or remove some if needed??

Second question, is there any other parts I should replace while I have the system evacuated?

Thanks
Michael

resharp001

What is your plan to evacuate the system before doing the work? If you're going to do all that work yourself, is there any reason you don't just fill the system yourself as well? You should be able to find the spec of both r134 and oil capacity. I bought an old Infiniti as a commuter car for dirt cheap....a/c wasn't working. I pretty much replaced everything you're doing, pulled a vacuum and charged the system based on the capacity specs I found online. I haven't had any issues in 2 years. Had never worked on an a/c system before that but I found it pretty straightforward with YouTube vids.....ChrisFix and a couple others. Obviously you're not going to get 100% of the oil out of the system but I really didn't find that to be a big deal and wasn't worried about putting almost the full spec back in. I'd think worse to not have enough than a little too much, though maybe I'm wrong.

Outside of what you listed there's not a whole lot else to replace. You're obviously not replacing the evap, and if there's nothing wrong with the lines no reason to replace those. Surely there is a pressure sensor in this JK system as well though.....I'd replace that while you're at it.

icrashbikes

I just did the condenser recently and recharged the system (with oil) with a buddy. He knows what he's doing so it seemed pretty simple. The specs are out there for sure, I'll see if I can dig them up. I have to do the compressor now because it's making awful noises

rockhousebadboy

Some compressors come with the proper amount of oil already in them and if not it's not that hard to find the specs. Buy a set of gages and a good scale and do it yourself.

resharp001

Michael, did you figure out how much PAG to add back in the system? I had a leak this week that completely drained my system. I've got lines replaced and the radiator shroud clearly shows the R134a capacity, but not the PAG. I presume it's PAG 46 but it doesn't even specify that. O'Reilly said it's 5oz PAG 46, but I sure don't trust their data given how hard it is to find this spec anywhere on the internet. Most vehicles it's a breeze to find the spec for.

Justin, do you know what you and your buddy added back in for oil?

icrashbikes

Funny you should ask, I have this sitting in the pile of parts next to the compressor


It's not what we used the first time, which was bright neon green. If I find that container in the garage I'll post what it was.

resharp001

I was more concerned with how much, but when I really got to thinking about it, regardless what the capacity spec is I had to have lost very little through this pinhole leak. My steering box, and frame rail was completely coated in ac oil, but when you really think about it, this is a situation where even one ounce of spilled, dyed oil can look like a huge amount. I really just thought about this logically and added back in 1oz, which is actually a good bit if the capacity is really 5oz like O'Reilly said. I got it back up and running today. I might actually call around see what local shops charge to just do an evacuate and recharge so I know for certain I have the right amounts. I've done this a few times on older cars, but I care about the jeep a bit more than a throwaway car that I would otherwise just say "meh, I got it close enough....time will tell". I'm really only into this repair for $137 for the new line, so if it's not some stupid amount it could be worth paying for a proper evac/charge just for peace of mind.