Re: R134 converted ac systems charge level ???
[Re: Ramrod39]
#3071738
08/26/22 11:53 PM
08/26/22 11:53 PM
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Joined: Feb 2003
Posts: 10,220 Someplace you aren't
SomeCarGuy
I Live Here
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I Live Here
Joined: Feb 2003
Posts: 10,220
Someplace you aren't
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I saw a chart recently, I’ll see if I can find it. Seems your number might be about what was on the conversion chart.
I want my fair share
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Re: R134 converted ac systems charge level ???
[Re: Ramrod39]
#3071740
08/27/22 12:49 AM
08/27/22 12:49 AM
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Joined: Jun 2003
Posts: 21,453 It's a dry heat
gtx6970
OP
Too Many Posts
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OP
Too Many Posts
Joined: Jun 2003
Posts: 21,453
It's a dry heat
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Find some R12. I tried converting to 134A on some old R12 systems and the results were not good. Interesting. a buddy of mines 68 Coronet was converted above method and his blows ice cold and has for over 5 years now. He just cant remember the exact amount he put in it. I charged mine this afternoon putting 36 ounces in it. Its cold, Not as cold as the above 68 Coronet. BUT,,,,, based on my above 80 percent rule. It could use a tad more I just dont want to go to far and risk damaging reed valves in the compressor
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Re: R134 converted ac systems charge level ???
[Re: IMGTX]
#3071784
08/27/22 10:44 AM
08/27/22 10:44 AM
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Joined: May 2019
Posts: 6,291 nowhere
Sniper
master
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master
Joined: May 2019
Posts: 6,291
nowhere
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As stated, R12 while hard to find is a better refrigerant.
And if you find it you need a license to buy it
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Re: R134 converted ac systems charge level ???
[Re: gtx6970]
#3071803
08/27/22 12:09 PM
08/27/22 12:09 PM
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Joined: Apr 2003
Posts: 12,237 Looking for a way out of Middl...
IMGTX
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I Live Here
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Looking for a way out of Middl...
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The car had been converted long before my purchase. It was empty when i bought it. Previous owner told me was bad condenser...yet ive found no signs ot that.
Ive replaced a bad hose .. and expansion valve and will be replacing the dryer as well. Ive got 36 ozs in it right now to ck operation and for any other leaks. So far...so good. On the drive home yesterday. It was cool and comfy...but feel like it could / hope would be a little better. I havent put a thermometer in the vent yet.
And planning to evac it back out . Change the dryer. Then pull a good vacuum on it for like an hour or so .
Was curious the anount required to recharge it. Ill start with the same 36 ozs for now and see what pressures i get. Some people convert by draining the R12 and refilling it with R134a & Ester oil and others will drain, flush, replace the oil in the compressor sump, and replace the hoses & O-rings. It's a crap shoot how it was done if you don't do it or see it done, but no biggie. If you run ester oil you will be fine if they didn't remove the mineral oil. When you replace the dryer if the o-rings are black they didn't replace them. Old school rubber was black. Newer HBNR are usually green but sometimes blue. I have found that the old rubber hoses and rubber seals will leak the R134a to the tune of about 12 oz per year. This usually means that in the spring you may need to top it off and you would be good for the year. If you are loosing more than that look for a bigger leak. If you replace all the hoses with newer "barrier' hoses and the o-rings/seals with the new HNBR then it should hold a charge a lot longer but the oem compressor seal was made for lower pressure R12 so it may still loose pressure over time. Good news is if you don't have a noticeable leak you should not loose any oil. As SRT said R12 requires a license but craigslist /ebay is a good source for people who are not interested in licenses. Just sayin...
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Re: R134 converted ac systems charge level ???
[Re: IMGTX]
#3071829
08/27/22 01:31 PM
08/27/22 01:31 PM
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Joined: Jun 2003
Posts: 21,453 It's a dry heat
gtx6970
OP
Too Many Posts
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OP
Too Many Posts
Joined: Jun 2003
Posts: 21,453
It's a dry heat
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The car had been converted long before my purchase. It was empty when i bought it. Previous owner told me was bad condenser...yet ive found no signs ot that.
Ive replaced a bad hose .. and expansion valve and will be replacing the dryer as well. Ive got 36 ozs in it right now to ck operation and for any other leaks. So far...so good. On the drive home yesterday. It was cool and comfy...but feel like it could / hope would be a little better. I havent put a thermometer in the vent yet.
And planning to evac it back out . Change the dryer. Then pull a good vacuum on it for like an hour or so .
Was curious the anount required to recharge it. Ill start with the same 36 ozs for now and see what pressures i get. Some people convert by draining the R12 and refilling it with R134a & Ester oil and others will drain, flush, replace the oil in the compressor sump, and replace the hoses & O-rings. It's a crap shoot how it was done if you don't do it or see it done, but no biggie. If you run ester oil you will be fine if they didn't remove the mineral oil. When you replace the dryer if the o-rings are black they didn't replace them. Old school rubber was black. Newer HBNR are usually green but sometimes blue. I have found that the old rubber hoses and rubber seals will leak the R134a to the tune of about 12 oz per year. This usually means that in the spring you may need to top it off and you would be good for the year. If you are loosing more than that look for a bigger leak. If you replace all the hoses with newer "barrier' hoses and the o-rings/seals with the new HNBR then it should hold a charge a lot longer but the oem compressor seal was made for lower pressure R12 so it may still loose pressure over time. Good news is if you don't have a noticeable leak you should not loose any oil. As SRT said R12 requires a license but craigslist /ebay is a good source for people who are not interested in licenses. Just sayin... Ive done all new O rings myself. I have no problem changing compressor oil. Thats easy . Just to be on the safe side. I will pick up a bottle of ester oil when I pick the dryer up today
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Re: R134 converted ac systems charge level ???
[Re: gtx6970]
#3071899
08/27/22 07:46 PM
08/27/22 07:46 PM
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Joined: Dec 2009
Posts: 20,647 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,647
in a cattle trailer down by th...
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The rule is to multiply the R12 fill spec by 0.9 then subtract 0.25 pounds from the result. Example 40 oz. of R12 = 2.5 pounds X 0.9 = 2.25 pounds minus 0.25 = 2.0 pounds of R134a. Keep in mind those small cans are only 12 oz. Additionally if you would like it to cool better put an auxiliary fan on the condenser then you can add a few more ounces of refrigerant. Keep the high side around 250 psi.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost conversion. 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: R134 converted ac systems charge level ???
[Re: gtx6970]
#3072067
08/28/22 12:50 PM
08/28/22 12:50 PM
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Joined: Mar 2010
Posts: 1,061 Atlanta, GA
mgoblue9798
super stock
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super stock
Joined: Mar 2010
Posts: 1,061
Atlanta, GA
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I start with 70% of R12 weight. Check your pressures after coming back from a drive on a hot day. Add more if pressures will allow. Buying a new modern design condenser made for r134 will help a lot with cold air temps as measured at the dash.
First choice though is R12. R134 is a smaller size molecule and designed to run at higher pressures, both of which can cause problems with leaks in an r12 system.
Last edited by mgoblue9798; 08/28/22 12:55 PM.
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Re: R134 converted ac systems charge level ???
[Re: Guitar Jones]
#3074100
09/04/22 05:32 AM
09/04/22 05:32 AM
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Joined: Apr 2006
Posts: 4,220 West Plains, MO
DrCharles
master
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master
Joined: Apr 2006
Posts: 4,220
West Plains, MO
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Best rule of thumb I have seen is to charge to a high-side pressure (in psi) of 2.2 to 2.5 times the air temp (in F) in front of the condenser/grille. That's how I do all my cars. If you're charging to 250 psi on an 80F day I think that's too much. Oh, and drain and flush as much of the old mineral oil as you can. It doesn't mix with the PAG oil used for R-134a, so it's taking up space in the system somewhere (even if it just sits in a low spot, usually the receiver/dryer).
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Re: R134 converted ac systems charge level ???
[Re: cudaman1969]
#3074369
09/05/22 05:21 AM
09/05/22 05:21 AM
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Joined: Jan 2003
Posts: 10,737 North Dakota
6PakBee
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North Dakota
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One thing I was told was to replace the hoses, the 134 will seep thru the old type hose. Your ends can be reused with the new hose. How is this possible with crimped ends? One of the reasons I'm asking is PS hoses. I've looked under all the rocks I could think of and never could find a procedure to re-use those hose ends with new hose. I would think A/C hoses are similar.
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: R134 converted ac systems charge level ???
[Re: 6PakBee]
#3074414
09/05/22 09:52 AM
09/05/22 09:52 AM
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Joined: Jun 2003
Posts: 21,453 It's a dry heat
gtx6970
OP
Too Many Posts
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OP
Too Many Posts
Joined: Jun 2003
Posts: 21,453
It's a dry heat
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Still with just the 36 ozs in it and the original receiver drier ( which I plan to change this week ) But so far, I think its working damn good
the OE water valve doesnt close so for now I have the heater core bypassed altogether . I just got an nos valve earlier this week I need to replace same time while drier is getting replaced
BUT,,,, center outlet temps are,,,,,,and This is sitting in the garage, at 85 degrees ambient temps , slightly above idle,
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