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EightBit posted:Pressures for R134a systems are the same across the board, that's just physics. Use the chart in the OP for reference, it will work for any R134a system. Is there a way to clean the evaporator? Cabin air filter is brand new. Ill try getting it to fail, it takes some time though now that I put that can in.
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Jul 11, 2015 21:01
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PaintVagrant posted:Is there a way to clean the evaporator? You can't really take the evaporator out to clean it without tearing up your dash and discharging the refrigerant. I've taken a vacuum cleaner to a house's evaporator before to get dust out, but that might not be feasible in a car.
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Jul 12, 2015 01:04
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I've got a 96 accord that to my knowledge has never had the A/C serviced. I hooked up the manifold and was reading around 60psi static pressure when I should be seeing about 80psi so that tells me I've got no liquid coolant in the system. Now when I engage the A/C I get 0psi/130psi and slightly cooler air out of the A/C (~3deg F difference) than ambient. I'm thinking that it's probably just refrigerant loss over ~2 decades and a refill should be fine (I can't get R134a as a DIYer here so it'll be a vac and recharge of R152a) or should I be looking at other things like the TXV considering I've got essentially no pressure on the low side?
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Jul 12, 2015 02:46
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mellodroid posted:I've got a 96 accord that to my knowledge has never had the A/C serviced. TXV is probably sicking closed. They can stick in either direction, and just decide to start working again whenever they feel like. When stuck closed you'll see low/no suction and lower than normal high side pressures. PaintVagrant: sounds like you may have the same issue, but yours is intermittent. But definitely get at your evap first to make sure it's not freezing over and is clean enough to have sufficient air flow and, as EightBit said - get those pressures when it's not working properly.
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Jul 12, 2015 18:27
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Motronic posted:TXV is probably sicking closed. They can stick in either direction, and just decide to start working again whenever they feel like. Can confirm, my first foray into AC last fall was for an intermittently sticking TXV with exactly these symptoms when it stopped blowing cold usually 10 or 15 min into a drive. Any time the low side gets toward 0 or vacuum with the compressor on there's a blockage somewhere and the TXV is the only designed restriction in the system. A frozen evap can reduce airflow at the vents depending on the design, so that's one thing to look out for. A couple of days ago I had my car recovered at the local tire place, took it home, flushed the lines, and put in a new condenser, drier, and reman compressor. The symptom was a slipping clutch above about 95 ambient and a resulting loss of cooling. The job went smoothly and the car now blows colder than ever but I really underestimated how foul and messy AC flush is even when your system is in good condition. That stuff gets everywhere and is really hard to clean up when your engine bay gets covered in flush mist that escapes the catch container.
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Jul 12, 2015 20:16
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PaintVagrant posted:Is there a way to clean the evaporator? I don't think there's any easy way to get to the evap in a car, but they do make an areosol evap cleaner you can try and spray in the box if you feel like taking half your dash apart. It just sprays on, and the condensate washes it off over time.
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Jul 13, 2015 00:02
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ExplodingSims posted:I don't think there's any easy way to get to the evap in a car, but they do make an areosol evap cleaner you can try and spray in the box if you feel like taking half your dash apart. You may need to take the dash apart to REPLACE and evap, but typically you can just remove the blower motor and access enough of it to see what's going on or even use an aerosol cleaner. On a lot of vehicles this is fairly straightforward - anything from "just climb under the dash and remove it" to "remove the glove box and then remove the blower" levels of annoyance.
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Jul 13, 2015 00:32
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Ran the car long enough for it to finally stop blowing cold air. Ambient: 75 Compressor working: Low: 35-40 High: 150~ Compressor not working Low: ~75 High ~100 Compressor short cycled like crazy at idle while compressor was working Compressor turns off with no real fanfare, the aux fans stay on like the compressor is running. But the pressures change and warm air blows through vents. Thoughts? I've got another can of refrigerant ready to go Edit: have not had a chance to get to evap core. Pulled the cabin air filter and felt plumbing, wasn't frozen on the outside or anything.
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Jul 13, 2015 00:45
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PaintVagrant posted:Ran the car long enough for it to finally stop blowing cold air. One thing worth noting is that once the engine has been running, you can't use the ambient air temperature to gauge the average temperature of the refrigerant. How long was it sitting before you got the "not working" readings? That should equalize pretty quickly with the compressor off.
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Jul 13, 2015 05:42
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EightBit posted:One thing worth noting is that once the engine has been running, you can't use the ambient air temperature to gauge the average temperature of the refrigerant. About 25 minutes or so.
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Jul 13, 2015 12:41
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I let it sit a while afterwards and the gauges did nearly equalize, something like 95/100 ish I think after not running a while.
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Jul 13, 2015 12:46
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I know that the high side is a bit harder to read due to having a larger range, but if you had enough difference after 25 minutes to say 75 low 100 high, then you have a blockage in your system somewhere.
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Jul 13, 2015 14:43
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To clarify and make sure we are on the same page: Cranked AC to max. While short cycling, was running around 35/150 while compressor was on. Eventually, the compressor turned off at the 25 minute mark and pressures changes to around 75/100. Let it sit that way for a while and they equalized to around 95/100ish, similar on both gauges after sitting for another 15 minutes or so So maybe 40-45 minutes total timeline.
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Jul 13, 2015 15:05
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So one of my room mates cars ac blows warm. Check the static pressures. They looked good. Check it running. Low side was 45psi. High side was 375 psi. What the gently caress is going on here? The compressor never shut off.
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Jul 16, 2015 22:52
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Sure sounds like a blockage somewhere, unless the ambient temp is well in excess of 110F.
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Jul 16, 2015 23:29
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kastein posted:Sure sounds like a blockage somewhere, unless the ambient temp is well in excess of 110F. That's what I was leaning towards. The low side line gets nice and cold though. That threw me off.
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Jul 16, 2015 23:52
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kastein posted:Sure sounds like a blockage somewhere, unless the ambient temp is well in excess of 110F. If it was a blockage wouldn't the low side be low?
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Jul 17, 2015 01:10
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The A/C in my girlfriend's 2007 Chevy Aveo 5 does not cool at all. I borrowed a gauge set from Auto Zone and the static pressure is correct and close to the same on the high and low sides, but the low side is a little higher than than the high side. The high side shows the right pressure for 92º, but the low side is pointing toward about 96º. Is that enough difference to mean there's probably an obstruction? It's near the top of the low side's range so it's harder to tell the exact temp it's lining up with, but it's definitely higher than 92º. The car had been off for around 2 hours at that point and the A/C has never been serviced before. Also, even though the compressor and fan turn on when the A/C is turned on, the pressures don't change at all. I figure that's probably bad, yeah? I don't know exactly how long it hasn't been cooling or how often it's been turned on even though it doesn't work.
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Jul 17, 2015 01:36
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FatCow posted:If it was a blockage wouldn't the low side be low? If it's a TXV not modulating properly, or a blocked dryer or something, then no. It'll still let gas though, but it won't be flashing off properly. Also 45psig is on the higher side for your suction line, so sounds like a restriction for sure. Or your condenser fan isn't running. Soup in a Bag posted:The A/C in my girlfriend's 2007 Chevy Aveo 5 does not cool at all. I borrowed a gauge set from Auto Zone and the static pressure is correct and close to the same on the high and low sides, but the low side is a little higher than than the high side. The high side shows the right pressure for 92º, but the low side is pointing toward about 96º. Is that enough difference to mean there's probably an obstruction? It's near the top of the low side's range so it's harder to tell the exact temp it's lining up with, but it's definitely higher than 92º. The car had been off for around 2 hours at that point and the A/C has never been serviced before. Are you sure the compressor clutch is engaging? Because unless you just don't have your gauges on there right, then you should see at least a little compression while it's running. ExplodingSims fucked around with this message at 03:12 on Jul 17, 2015 |
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Jul 17, 2015 03:10
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ExplodingSims posted:Are you sure the compressor clutch is engaging? Because unless you just don't have your gauges on there right, then you should see at least a little compression while it's running. I'm pretty sure it was. Part of it definitely stopped spinning when the A/C was turned off and the fan turned off as well. And I think the gauges were on right too since it was showing pressure and didn't sound like anything was leaking. It's a Mastercool gauge set with manual couplers and the couplers were secure and their service ports were open. I'll try again tomorrow and double-check everything. Maybe take a video if it's still doing the same thing.
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Jul 17, 2015 03:46
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Redoing the R152 conversion on my 535i tomorrow since the drat high pressure switch leaks, as does the schrader valves. Pressure switch is pipe thread. Do I need to put anything on it? Seems like teflon is a no-no, do I just install it dry? Found out that these cars have no low pressure switch... It makes filling them nice, but it seems kinda stupid since the compressors are $500 new... When I do the custom condensor, I think I'm going to do a binary switch install since I don't want shrapnel in a parallel flow condenser. drat thing is also starting to melt the fusebox at the condenser fan fuse. I might switch it to a relay setup. Also doing the brother in law's 2000 Civic. It was working good then quit. Condenser fan plug was melted. Replaced plug and all was good. Now it quit again... This time is evac'd all it's refrigerant. I can't find a leak except the schrader valve on the low side. I'm going to replace it and see if it holds vacuum tomorrow.
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Jul 17, 2015 06:52
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Sadi posted:So one of my room mates cars ac blows warm. Check the static pressures. They looked good. Check it running. Low side was 45psi. High side was 375 psi. What the gently caress is going on here? The compressor never shut off. Make sure the fans are running. I saw this same symptom on a friends mazda3 with dead fan. Tossed a bigass box fan on high in front of the car and the pressures magically went to where they were supposed to be.
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Jul 18, 2015 03:02
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House A/C chat -- I finally got around to replacing my contactor and capacitor on the outdoor unit. Both were obviously original, about 16 years old. Can replacing those two things make it run smoother and quieter / start up smoother? It seems like it does. I can understand the startup being smoother, the capacitor was probably fully poo poo, but would that make a difference during actual operation?
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Jul 18, 2015 14:13
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EVERYWHERE 
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meatpimp posted:House A/C chat -- I finally got around to replacing my contactor and capacitor on the outdoor unit. Both were obviously original, about 16 years old. Can replacing those two things make it run smoother and quieter / start up smoother? It seems like it does. I would think so given that the capacitor usually has two sides, one for start and one for run.
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Jul 18, 2015 14:25
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I have a 2009 VW Rabbit that's never had it's A/C serviced (176k miles). It still gets cool, but not as frosty as it used to, so I had Firestone do their $10 A/C check while I was getting my oil changed today. They said they didn't detect any leaks, but that coolant pressure was very low. I'm wary of those $30 walmart recharge kits, but how much should a service cost? They quoted me about $250.
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Jul 19, 2015 18:12
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So both the Avalon and Ion have been wheezing out barely cool air for awhile. The Ion's been putting out ~60F on warm days (55 at speed), Avalon about 65 (60 at speed). Both cars showed equal readings with gauges and compressor off. Avalon took about half a can before it stopped short cycling - added another half a can, and it got up to 30 PSI (~95F ambient). Another half can, and it's sitting at about 40 PSI, and blowing a nice frosty 38F from the vents on low, low to mid 40s on high. At idle, sitting in the sun. The Ion took a full can (total system capacity is only 14.5 oz  ), and it's still only up to 35 PSI. But even with the fan on high, it's blowing a titty freezing 38-40F. At idle, 95 degrees in the shade.I think both could still use a little more, as the pressures are still a little on the low side (both low and high side are a bit low for the ambient temp). AutoZone has 2 for $20, so I'll probably grab two more and keep one as a spare.
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Jul 21, 2015 02:08
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What're the high side pressures?
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Jul 21, 2015 02:13
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Avalon in the low 200s. I don't really remember beyond that. I'm actually thinking the gauges may have been hosed - I got my car up to a little under 40 low/190 high and it started short cycling (it'd run for half a second, shut off for 2 seconds, etc), so when I finished filling the Avalon, I just got it to where the compressor was cycling on and off every minute or so with temp vents in the high 30s/low 40s. I didn't pay enough attention to the gauges when the Ion started short cycling, just recovered enough refrigerant to bring it down to where it cycled normally. They were definitely really beat up gauges (cracked lenses etc). I'll buy my own gauges and re-evaluate, or just get a friend with a Robinair to do a full recovery/recharge on both. e: the gauges also showed that my car had <5 PSI when I started, but it was still blowing cool, just not cold. Pretty sure the low pressure switch would have kept anything from happening at 5 psi. randomidiot fucked around with this message at 04:11 on Jul 21, 2015 |
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Jul 21, 2015 04:08
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Yup, those gauges were WAY the gently caress off. My car started short cycling today (and the compressor was putting enough load on the engine that the car jerks pretty hard + belt squeals when it cycles). Stuck one of those DIY in a can gauges on... it almost pegged the gauge.  (it's an empty can that's been sitting around for a few years.. well, was empty, it actually filled up a bit I think)Needless to say, a significant amount was recovered, and it's not short cycling now. Vent temps are right at 38 now, whereas they were in the teens last night. randomidiot fucked around with this message at 18:26 on Jul 21, 2015 |
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Jul 21, 2015 18:23
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Can I leave the old PAG oil in if I convert an R134a system to R152?
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Jul 22, 2015 17:13
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PBCrunch posted:Can I leave the old PAG oil in if I convert an R134a system to R152? Yep.
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Jul 22, 2015 18:40
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Quote not edit gently caress me.
Wasabi the J fucked around with this message at 19:40 on Jul 22, 2015 |
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Jul 22, 2015 19:36
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Update on my ac install nightmare: Big O hooked up gauges for free, I'm apparently several ounces low in refrigerant, and the readings are exactly the same as what they were when I left the shop who installed it; 145:35 @ 100° Thank gently caress I've been afraid to use it for fear of damaging another loving compressor. Wasabi the J fucked around with this message at 19:41 on Jul 22, 2015 |
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Jul 22, 2015 19:39
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I'm trying to diagnose the weak R12 AC in my NA Miata. I got a cheap universal manifold gauge set on the internet but now its here it seems like it wasn't really R12 compatible as was listed because there's no fitting that fits the high pressure port. Am I missing something or is this just a typical dumb cheap set?
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Jul 25, 2015 07:48
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Unlike R134a, R12 didn't have 100% standardized fittings across brands. When I charged my Blazer with R12, I was using R134a gauges and adapter fittings; i had to hunt through several different stores before I found one that fit my high side fitting. You might have to do the same; I've found O'Reilly's and Carquest are best for R12 stuff. If your gauge set has R134a fittings, I'd use those and get adapters, as you're much more likely to find them than actual hose fittings these days.
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Jul 25, 2015 08:23
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Enourmo posted:Unlike R134a, R12 didn't have 100% standardized fittings across brands. When I charged my Blazer with R12, I was using R134a gauges and adapter fittings; i had to hunt through several different stores before I found one that fit my high side fitting. You might have to do the same; I've found O'Reilly's and Carquest are best for R12 stuff. The gauge did come with the R134a quick connectors so I took your advice and just tried to get a set of adapters to fit my pipes. Haven't had the chance to go try fitting them yet but they seem to be set up with a full valve core. Assuming they match up what's the best way to attach these to the existing valves without releasing a giant middle finger to the ozone layer?
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Jul 26, 2015 14:40
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They're meant to screw on to the existing fittings without having to vent anything. They should be designed so that the threads are engaged and sealing before the adapter depresses the schrader on the R12 fitting. Just screw it on and you're good to go just like usual.
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Jul 26, 2015 20:33
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Unfortunately the ones in Japan apparently don't work quite that way and I got a very cold air intake.  I think I'm gonna wave a white flag here and take it to a shop before I lose a finger. Thanks for all the help anyway.
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Jul 27, 2015 13:36
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Finally bought my own set of gauges. Holllly poo poo were those loaner gauges WAY the gently caress off. I think there's a blockage somewhere in the Saturn - the low side was in the 30s, the high side was sitting at a touch over 300. Certainly explains why the mileage went to poo poo, I'm amazed it wasn't short cycling. I just went ahead and went with the high side readings for the charge (and ignored the low side) and got it down to ~250, which is at the low end for 90F ambient (sun was down). The low side was still in the 30s afterwards, and vent temps are right at 40. I don't know if the funky variable displacement compressor has anything to do with the odd pressures (probably not). The Avalon I managed to get drat close the other day after I gave up on the gauges - it was a touch low when I checked it tonight, but not by much. Vent temps are right at 40 on it as well now, but now the belt (or tensioner) is squeaking a little. 
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Jul 28, 2015 06:18
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So I have a 1991 Toyota Soarer (UZZ32) which was almost certainly originally sold with R12. Toyota only fitted R134a to 1994+ models. It needs a new condensor. It currently has R134a push-on type fittings which look to be as old as the car. I have a new condenser, new receiver/drier, some cans of Dust-Off, and all the equipment necessary to use it. The system is still sealed with an unknown refrigerant and is holding pressure. What kind oil should I use and how much will I need to replace? This is the question which has been on my mind for the last few days and I'm still not sure how to figure out the correct answer. Compressors are no longer available and unique to this cars very limited production run. I doubt I'll ever find one on anywhere other than from a breaker. I don't really want to cock it up. I also have another 1991 UZZ32 which was made a few weeks earlier, which has R12 screw-on fittings and an otherwise identical looking AC system. I also don't know the charging weight, but I was just going to look up whatever a SC400 uses and convert as required.
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Jul 30, 2015 15:19
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