A/C Charging with Easy Cheap Safe Alternative Refrigerant
08-09-15, 09:54 PM
#326
The kid's Audi S4 is in the shop so he needs to drive his winter car (the RX) tomorrow. We put the R152 in and got the vent temps to 38. Easy peasy. Then while taking off the high line he lost some pressure. On an emissions compliant People's Republic of Austin turbo, there are a lot of vacuum hoses and harnesses there. Still blows 42 and we're replacing the drier tomorrow when it arrives from Orreillys so we'll 'dust' the engine bay and do it again!
Thanks, Jack. Great stuff.
Jim
Thanks, Jack. Great stuff.
Jim
08-10-15, 09:06 PM
#327
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Cleaned and flushed all AC lines. Blew them out with compressed air. Replaced ALL O-rings,compressor, and condenser. Added the proper amount oil and pulled a vacuume. High side is at zero low side is a -30. Has held for almost 2 hours. Gonna check gages in the morning and hope they havent leaked down. Will fill tomorrow after work. Does anyone know what kinda working pressures I should be achieving? Mike
Last edited by liznmike; 08-10-15 at 10:45 PM.
08-11-15, 04:07 PM
#328
Cleaned and flushed all AC lines. Blew them out with compressed air. Replaced ALL O-rings,compressor, and condenser. Added the proper amount oil and pulled a vacuume. High side is at zero low side is a -30. Has held for almost 2 hours. Gonna check gages in the morning and hope they havent leaked down. Will fill tomorrow after work. Does anyone know what kinda working pressures I should be achieving? Mike
You need 15.8 to 18.2 oz of R152a. The last time I charged I used an electronic mail scale. Installed a full can (10 oz) then switched cans. I set the can on the scale, hit the 'tare' button to attain a zero read out. Then I charged another 7 oz. I expect to lose about an ounce an a half in the hoses on an R12 connected car.
Done.
Last edited by jackhild59; 08-11-15 at 05:04 PM.
08-11-15, 05:03 PM
#329
Top Secret Technique:
In the absence of a scale, I have developed the following technique to attain a pretty nice charge.
1.) 90* day.
2.) Pull that deep vacuum.
3.)Bleed all three hoses to eliminate all air.
4.)Prop the gas pedal to make the engine run at about 1500rpm.
5.) Set the controls to recirculate, low speed fan, turn on the a/c button.
6.) Charge in the first can, liquid first.
The low pressure switch should start to cut-out at about 20-25psi and cut back on about 40psi. The compressor should cycle on and off at those pressures. Center vent temps should be low to mid 40's. Allow interior of car to cool off.
4.)Advance fan speed to about 1/3. Compressor should no longer cycle.
5.)S-l-o-w-l-y add small amounts of R152 from second can. Add a bit, wait a bit. add a bit, wait a bit. Eventually the low side pressures will start to drop and the compressor should start to cycle again.
7.)Shut off the valves on your gauges and remove the hoses without losing all your charge.
At this point, you should be pretty close.
-Jack
1.) 90* day.
2.) Pull that deep vacuum.
3.)Bleed all three hoses to eliminate all air.
4.)Prop the gas pedal to make the engine run at about 1500rpm.
5.) Set the controls to recirculate, low speed fan, turn on the a/c button.
6.) Charge in the first can, liquid first.
The low pressure switch should start to cut-out at about 20-25psi and cut back on about 40psi. The compressor should cycle on and off at those pressures. Center vent temps should be low to mid 40's. Allow interior of car to cool off.
4.)Advance fan speed to about 1/3. Compressor should no longer cycle.
5.)S-l-o-w-l-y add small amounts of R152 from second can. Add a bit, wait a bit. add a bit, wait a bit. Eventually the low side pressures will start to drop and the compressor should start to cycle again.
7.)Shut off the valves on your gauges and remove the hoses without losing all your charge.
At this point, you should be pretty close.
-Jack
08-13-15, 03:35 PM
#330
Dont remember seeing this in any of the previous posts. It's a 2004 Dupont preso to SAE about 134a vs 152a and exceedingly geeky. I expected it to be a "152a is evil" piece but after reading it I dont think it was. Slide 22 was interesting in that it noted that PAG is even more miscible in 152a than it is in 134a suggesting that 152a in PAG cars is a-ok. Shouldn't be any PAG in an FC but you never know.
This YouTube is interesting when he does a flammability test with the R152a and a MAPP torch at about 2:30.
This YouTube is interesting when he does a flammability test with the R152a and a MAPP torch at about 2:30.
08-15-15, 02:01 PM
#331
Swapping the drier with a new one after running for 4 days on 152a in 100-105 degree Austin summer heat. Worked beautifully.
I turned the drier over to drain the oil out. I was curious how much of the mineral oil had migrated out of the compressor and into the bottom of the drier. But there wasn't any. It was empty. Is that expected? If the mineral oil isn't as miscible in 152 as it is in 12, I would have thought the compressor would have pumped it all into the drier but no further.
The drier ports are nice and clean so there wasn't any PAG contamination.
I'll put the recommended amount of ester oil in.
I turned the drier over to drain the oil out. I was curious how much of the mineral oil had migrated out of the compressor and into the bottom of the drier. But there wasn't any. It was empty. Is that expected? If the mineral oil isn't as miscible in 152 as it is in 12, I would have thought the compressor would have pumped it all into the drier but no further.
The drier ports are nice and clean so there wasn't any PAG contamination.
I'll put the recommended amount of ester oil in.
08-16-15, 07:29 PM
#332
MECP Certified Installer
So, interesting thing today...
After work I threw in our ozone machine, I have been doing this for a few weeks to get that musty smell out of the vents. I let the car run for about 20 minutes with the ozone machine, AC off but the blower full blast on recirculate.
About 10-15 minutes later I hopped in the car and went to go home and the AC compressor kept trying to stall the engine. The first time it nearly died and then the second time same thing. I revved the engine a bit and everything seemed normal other than the AC wasn't cooling the car. I kept driving and turned the AC off and turned it back on and the car wanted to stall again. I turned it back off and then on and revved the engine and everything seemed to be working again. The AC became cold, but not chilly as before.
Question is, did my damn expansion valve get stuck. When I got home I popped the hood and my return line to the compressor was dripping like a sweaty person. The AC had only been on less than 3 minutes.
I'll hop down there and test it again here in a minute. Maybe I heat soaked the valve (it's thermoregulated) I dunno.
Post back up here in a few minutes.
After work I threw in our ozone machine, I have been doing this for a few weeks to get that musty smell out of the vents. I let the car run for about 20 minutes with the ozone machine, AC off but the blower full blast on recirculate.
About 10-15 minutes later I hopped in the car and went to go home and the AC compressor kept trying to stall the engine. The first time it nearly died and then the second time same thing. I revved the engine a bit and everything seemed normal other than the AC wasn't cooling the car. I kept driving and turned the AC off and turned it back on and the car wanted to stall again. I turned it back off and then on and revved the engine and everything seemed to be working again. The AC became cold, but not chilly as before.
Question is, did my damn expansion valve get stuck. When I got home I popped the hood and my return line to the compressor was dripping like a sweaty person. The AC had only been on less than 3 minutes.
I'll hop down there and test it again here in a minute. Maybe I heat soaked the valve (it's thermoregulated) I dunno.
Post back up here in a few minutes.
Last edited by jjwalker; 08-16-15 at 07:31 PM.
05-17-16, 11:36 AM
#336
MECP Certified Installer
It ended up actually being the bearings on the AC compressor. I ended up having to take the belt off of it to stop the howling and screaming. Whenever I get the chance I need to replace the face of the AC compressor but it is low on my list of priorities on the car right now. It was really nice to have cold AC for a while Jack, I appreciate you coming over to help me with that.
05-17-16, 11:50 PM
#337
It ended up actually being the bearings on the AC compressor. I ended up having to take the belt off of it to stop the howling and screaming. Whenever I get the chance I need to replace the face of the AC compressor but it is low on my list of priorities on the car right now. It was really nice to have cold AC for a while Jack, I appreciate you coming over to help me with that.
Get a used compressor. We'll recharge it again.
07-25-16, 07:37 PM
#341
Admitted 'rexaholic'
Guys is there an alternative refrigerant I can just add to my 89 that has R12? It blows cool, but not cold. R12 is way $$ on ebay so hoping there was something that would mix and not cause issues.
07-25-16, 07:52 PM
#342
MECP Certified Installer
07-26-16, 06:59 AM
#344
Mixing refrigerants can sometimes yield a blend that doesn't perform as well as either pure refrigerant.
07-26-16, 08:42 AM
#345
MECP Certified Installer
Jack, considering the current price of R-12, I suggested just topping off with r-152a. R-12 and R-152a aren't going to be oil and water type of thing as R-152a pressure and expansion rates are similar to R-12.
$12 for 6 cans of computer duster or $103 for 3 cans of R-12? ***** worth more than gold...Wish it didnt eat holes in the atmosphere.
08-02-16, 09:33 AM
#346
MECP Certified Installer
Jack, help!
I somehow fixed the wailing compressor issue with crude hand tools and beer.
My freaking refrigerant leaked out of the high side schrader valve. It took a LONG time, but my UV light doesn't lie.
I am going to get my hands on some manifold gauges, side can tap, and a vacuum.Here is my issue though. R-12 gauges are exceedingly hard to find and expensive.
Can I just throw the R-134a adaptors on and use an R-134a manifold gauge set to charge it?
I somehow fixed the wailing compressor issue with crude hand tools and beer.
My freaking refrigerant leaked out of the high side schrader valve. It took a LONG time, but my UV light doesn't lie.
I am going to get my hands on some manifold gauges, side can tap, and a vacuum.Here is my issue though. R-12 gauges are exceedingly hard to find and expensive.
Can I just throw the R-134a adaptors on and use an R-134a manifold gauge set to charge it?
08-02-16, 12:17 PM
#348
MECP Certified Installer
