I would guess that too. It's just a bog-standard bearing, I've had multiples go noisy on me. Unfortunately, the same metallic scrape-like sound can be made by the alternator bearings. I'd just take the belts off to see if you can isolate the rotating part that's not smooth.Originally Posted by cordes
https://www.rockauto.com/en/moreinfo...097805&jsn=432
Thanks. This noise started as soon as I installed the AC and goes away when I remove the belt. I'm thinking It must be the pulley for the AC. Thanks for the link. I'll be looking into that for sure.
I found this flow chart tonight. Looks like I most likely added too much oil to the system. I can't think of anything else which would cause the high pressure on both sides. The system was dead empty and held a decent vacuum before I added 7oz of oil. After the pulley noise, I'm thinking they might have just removed the belt and the system leaked down over the years since the car was in Aspen. I will remove, drain, and flush the condenser and go from there. I'll probably not add oil at first since I'm sure the compressor must be full still. I really wish there was a better way to know how much oil was needed in a system.
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https://www.sanden.com/objects/SANDEN_SYSTEM_DIAGNOSIS_CHART.pdf
I used a mechanics stethoscope to find my issue in the past when my pulley was bad
Last edited by chromguy; 06-12-2020 at 08:13 AM.
Regards,
Miles
DD '87 Sundance T1, SLH with rear disks
'87 CSX #432 2.5 CB TII, SLH
Well, the noise is officially eliminated with a pulley swap. My pressures are still very high for how much refrigerant was put in. I'm going to flush out the condenser and go from there.
If anyone has a link to the Chrysler A590 C171 AC compressor suction/discharge gaskets in perhaps a 10 pack for cheap, please let me know. I found a kit with all of them, but I predict that I'll need more of these than the rest. They were a doozy to find since everywhere listed the 90 Voyager as coming with a different type of gasket. It was very frustrating to track them down today.
Another question if people are still following along...
What are you guys using for your conversion factor going from R12 to R152a? I have seen varying numbers ranging from .85 to .57. That makes a huge difference in how much you put in.
Here is a link where I saw the molecular weights and used some math to determine he's come up with approximately a .57 ratio.
https://www.s10forum.com/threads/how...39;s%2024%20oz.
ETA: After taking a couple ounces of oil out of the system it did charge up much better this time. I never really saw the temps I was expecting and the min temp ended up being about 50*. However, if I were to use the .57 ratio and multiply by the 29oz. the system called for with R12, I blew right by that before checking things. That would be 16.5oz total and I think I put in 2 cans before I looked at my temp gauge. Perhaps I was conflating the different ratios with the difference between R152a and R134, and the ratio between R12 and R152a. More thinking to come...
yeah its much less by molecular weight than r12.
i thought i touched on that earlier. not sure though.
Brian
You probably did and I missed it. I'm certainly learning a ton by doing this and I'm glad that I'm doing the air duster. This has been a very cheap way to make mistakes.
no worries... especially because duster is cheap lol.
Brian
No kidding. I can't believe what people pay for the R134 stuff in the parts store. It's crazy.
Bought 3 10oz cans at Harbor Freight for <$5/can (no oil in it)
Alright. I changed out the condenser today and pulled a vacuum. It held, so I put two 20oz cans in there when it calls for 29oz of R12. I figured with what I purged off, I'm close to the roughly .6 of R12 that should be required.
That said, My pressure on the low side is still 40PSI and the high side is about 230PSI or so. I really don't understand that. Also, the compressor didn't seem to cycle on and off at all. It was only blowing 60* air out too.
I noticed that the heater bypass valve is stuck on full open into the HVAC box. Could that be part of my issue? I've read that they're really unnecessary, but I'm guessing that if the cable for the blend door isn't as tight as it used to be and the foam isn't as good as it used to be, that could be inhibiting things quite a bit.
At this point I'm running out of ideas short of throwing an evaporator at the thing.
OK. I'm feeling a little better about my pressures after checking this chart. I've clearly been looking at R12 weights and pressures way too much. Seems like my pressures are a little on the low side if anything given it was nearly 90* out today and I was in the sun when conducting the test. I guess I should replace that bypass valve and report back. Thanks again for all the moral support everyone. I feel like an idiot stumbling through this, but that's how I learn best unfortunately.
It sounds like you may have a stuck expansion valve. Look at your receiver/drier (bottle on right fender) the sight glass should be clear with liquid, no bubbles. Compressor cycles only when either the low pressure switch opens or on newer cars the anti-icing switch opens. Some vehicles Ford and GM primarily have used a cycling compressor orifice tube system. Some newer cars do not use the heater bypass valve, I have a 1992 Imperial EATC system in my car, it has no provision for water cutoff.
High side pressures will be higher with R134 than R12, the pressures coincide at 60 psi for temperature, below 60 R134 runs lower, above 60, higher.
Here is another handy chart, and some neat math for those who think they might want to give this a try also.
Using this information I got from a random site, and knowing that the single system Voyager takes 29oz, or 822.136g here is how that looks.R12 is 120.91 grams per mole
R134a is 102.03 grams per mole
R152a is 66.05 grams per mole
The formula:
(<charge weight of original refrigerant in grams> * <molecular weight of desired refrigerant>) / <molecular weight of original refrigerant> = Charge weight of desired refrigerant in grams
[(822.136)*(66.05)]/(120.91)= 449.1g
After converting that back to Oz so I can estimate the cans, I come up with 15.84oz
I put in two cans, but perhaps my purge isn't taking nearly as much out of the cans as I would anticipate. I wonder if the extra 4oz is killing me due to too much oil? At this point I can't imagine that's the case. I'll definitely be reporting back after the replacement heater bypass valve.
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Thanks for that info. Unfortunately, I don't have a sight class on the receiver/drier. It's good to know the compressor doesn't cycle on the older cars. Maybe I'll take another video and post it up after I do the bypass valve.
Don't just slam 2 cans in there. Put one in and slowly put the other can in while watching the vent temps. They will slowly drop and then rise again. Once it hits its peak low and then rises 1 degree, then stop.
Brian
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This will take a while. Like add a little , wait 5 min, note temps, add a little more, wait 5 min, take note of temps etc.
I followed this advise last month and it worked great! Thanks Brian
Regards,
Miles
DD '87 Sundance T1, SLH with rear disks
'87 CSX #432 2.5 CB TII, SLH
I thought I waited a while with this last go, but I certainly didn't wait 5min. Once I get the bypass valve in I think I'll know if I need to give it another go. I will say that I drove the van to Indiana today and I was comfortable when the outside temps were 93*.
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