The 2024 A/C Thread: I've been telling you it's not Freon for 11 damn years

The Something Awful Forums > Discussion > Automotive Insanity > The 2024 A/C Thread: I've been telling you it's not Freon for 11 damn years

Krakkles: May 5, 2003

That kind of raises a question I've been thinking about - I don't know if I'm up to actually doing major repairs on my A/C, but I'd like to at least test and narrow down what the problem is before I make that judgement. HarborFreight has this on special, their AC manifold gauge and (better of two) vacuum pumps ... it sounds like this is the right tools, are these decent? If I'm probably only going to test, does getting the pump as well make sense?

I think I'm gathering the pump is part of testing too, so I'm leaning toward both.

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# ¿ Jul 18, 2021 18:52

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# ¿ May 11, 2024 08:16

Krakkles: May 5, 2003

IOwnCalculus posted:

Picture because why the hell not:

TJ's air conditioning was short cycling and doing fuckall. Can't find any obvious signs of a leak, and when I hooked it up pressures were just barely low enough to confirm no liquid in the system. Took most of a can before it stopped short cycling and held steady at the pressures shown here (about 32 low, 180 high). Temps are about 75-80 and 100% humidity, seeing as it was raining most of the time I was working.

Vent temps got down to 39 after charging. The only thing slightly odd is that the FSM's published pressures want to see a lot more high side than I'm getting:

I'm going to let it be for a while because it's definitely working better now. If it acts up again, the FSM's diagnostics point towards a restricted accumulator, restricted evaporator, or a dud compressor. Also ordering a leak sniffer because for less than $30, that seems better than injecting dye.

I'm doing this shortly on my XJ, link me that leak detector, please!

# ¿ Jul 24, 2021 00:14

Krakkles: May 5, 2003

Alright, I have another dumb question: If I hook that manifold up to check pressures on a system that I haven't touched yet (but am pretty sure has some Freon* in it), how do I take the manifold back off without venting to atmosphere? Where else would it go?

# ¿ Aug 6, 2021 23:29

Krakkles: May 5, 2003

Alright, that makes sense. Thank you. Sorry I called it Freon :v:

# ¿ Aug 7, 2021 03:42

Krakkles: May 5, 2003

Finally attempted to recharge/diagnose my Jeep ('00 Cherokee) today - hooked up the gauge set (all with a healthy dose of safety - leather gloves, glasses, long sleeves), checked the initial pressure.

Hmmm. Zero. Fiddled with things, trying to see if I'd hooked something up wrong or left a valve closed (the ones at the line ends, not the ones on the manifold!), no dice. I think it actually was totally empty.

Tried charging it, had some difficulty because, as far as I can tell, the can tap I bought is a piece of crap, but managed to get some pressure and the gauges wiggling:

I stopped when I got the lowside pressure while running to 80psi and short cycling continued - it looks like some repairs are needed.

Looking back at it now, I think I shouldn't have tried to charge - if it's at 0psi, there's pretty definitely a leak. The only upside I can come up with is that there should be a healthy dose of UV dye somewhere that I'll be able to find (I'm planning to look with a UV light after dark tonight), and I've no idea how I'd find it without that.

That said, because I got to 80psi with continued short cycling, it sounds like I'm probably out of my depth at this point and need to find someone to do repairs.

The one really frustrating thing - the can tap I got (https://smile.amazon.com/gp/product/B07D18WVFD/) seems to have a problem fully opening the can, which is easily resolvable by replacing an o-ring ... which I can't do, because it's on a pressurized can of refrigerant. I think two questions arise - is there any chance I got to 80psi but still didn't put enough refrigerant in to resolve the issue because the flow is bad (I don't think the can is nearly empty, I can still hear a fair amount of material inside) and ... what the hell do I do with it now? Can + tap to hazardous waste / dump?

Krakkles fucked around with this message at 19:02 on Oct 3, 2021

# ¿ Oct 3, 2021 18:58

Krakkles: May 5, 2003

PitViper posted:

Is your can one of the new self-sealing ones? I've been using my old taps with those, but it's a bit counterintuitive because 100% closed/open is functionally the same, because the can seals itself with the valve all open. Halfway between open/closed gets the flow through the gauges to fill the system.

And yes, 80psi on the low side is.... Concerning. How hot was it when you were charging? I've seen more than 40-50psi even when filling from empty after a compressor replacement, but I try not to work when it's 100°+F outside. The short gif is kind of hard to understand, but seeing low rose/high fall when the compressor cycles off is expected.

Last vehicle I did the compressor shirt-cycles a lot during fillup, but it was a nearly empty system to start (bad high side valve, replaced with some pressure left in the system) so getting enough volume to keep the low pressure cutoff from hitting took a while.

gently caress, apparently it is. Does that mean I can take the tap off without the can discharging? And, should I get a different tap? I'm actually glad to hear/connect that - It seemed like there was a midway point (between open and closed) that it hissed and seemed to bounce the gauge more.

Yeah, the pressure / temperature is the real reason I stopped - I figured I'd post about it and reconsider based on what y'all said. It was mid-70s when I started and is now 87, so ... temperature is a factor. When I shut the car off, it was showing 100psi high and low. Which ... at least they match, but also ... that seems wrong.

# ¿ Oct 3, 2021 19:32

Krakkles: May 5, 2003

Nah, I�m just trying to be respectful based on the OP and general concern for the environment. I�m comfortable with it.

Is using this style tap (half open) significantly reducing the flow out of the can compared to the appropriate tap? I�ll definitely buy a different tap and swap it if it�ll save me a lot of effort, but if it�s not that big a deal, I�ll keep trying tonight. :v:

# ¿ Oct 4, 2021 01:08

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# ¿ May 11, 2024 08:16

Krakkles: May 5, 2003

Nah, you're not wrong to hedge, it's all good.

I ordered the other style of tap, which is due to arrive Tuesday. I do feel like when I got pressure coming out, it was fiddly and probably not flowing very quickly, so the right tool might help with that. Thanks, guys! I'll update when I work on it again

# ¿ Oct 4, 2021 03:52

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