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#1 |
![]() Join Date: Dec 2005
Location: Delanson, NY
Posts: 911
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I am getting code 09 which is low Freon. I am running through the diagnostic in the 1990 FSM and it says to add 1 lb. of R12. The AC clutch is not engaged so my question is, will I be able to add the Freon through the low side of the system without the AC clutch engaged? Has anyone done this in the past?
Since the car is almost 35 years old I have read that the seal at the front of the compressor is the likely leak point. Any suggestions on a source that will rebuild the compressor for either R 12 or R 132. BTW I know I can't mix the two refrigerants, Should the compressor be the culprit maybe it is time to convert the car to the current refrigerant. Thoughts? Thanks.
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1968 convertible Lemans Blue, 1986 coupe Medium Blue NCRS Top Flight (sold), 1990 ZR1 #2529 Red NCRS Regional and National Top Flight (sold), 1990 ZR1 #2124 Charcoal Metallic NCRS Top Flight 2010 & 2018, 2003 Anniversary Red Convertible (sold) |
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#2 |
![]() Join Date: Jan 2006
Location: Decatur, AL
Posts: 1,112
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In my experiece is unless it is totally out, the compressor will kick on as you add the 1lb. If it doesn't start you can unplug the pressure sensor on the a/c line and jump it to manually start the compressor. I am not 100% sure exactly which plug it is as I would refer to the FSM if needed so it would be good to look up the exact plug location just in case but I think you will be fine getting it to come one with just the can of freon when you crack it open. I still run R12 too.
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Corvette95 Registry and Forum (*************) 1989 C4 Conv Wht/Gry Auto Hardtop Top Flight SOLD 1995 C4 Coupe Purple/Blk 6 Speed 1989 C4 Conv Wht/Red Auto SOLD 1996 C4 Conv Black/Tan Auto SOLD 1994 C4 Coupe Wht/Blk SOLD 1995 C4 ZR-1 White/Gry #278 Dual Dunn Head SOLD 1986 C4 Coupe Black/Red 4+3 SOLD 1990 C4 ZR-1 Red/Red #0454 |
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#3 |
Join Date: Mar 2021
Location: Crawfordville, FL
Posts: 216
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If the Freon level is that low that the compressor will not engage, you have to bypass or short the low pressure switch to turn on the compressor to get Freon into the system. You will not be able to add Freon to the system unless the compressor is operating using the store-bought cans of refrigerant. And the amount of Freon needed will depend on the low and high pressures in the system, which is way more accurate than saying "add 1lb. of R12". which may be a great excess.
There are many places for leaks to occur, mine was from the Schrader valve on the high pressure line and was cured when I replaced that valve stem. You have to find the leak source before just adding more Freon (which can be done with a leak detector or a UV light dye detector) before assuming anything or just replacing parts hit and miss' till you find it. If you just refill the system you are wasting your time and your money as the leak will persist and you will soon be back where you started from. You need to do some research and read about the AC system and watch some videos on this, which is way more valuable than just getting some advice, good or bad, on here. Or bring it to a professional and have someone else look at it. |
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#4 | |
![]() Join Date: Dec 2005
Location: Delanson, NY
Posts: 911
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1968 convertible Lemans Blue, 1986 coupe Medium Blue NCRS Top Flight (sold), 1990 ZR1 #2529 Red NCRS Regional and National Top Flight (sold), 1990 ZR1 #2124 Charcoal Metallic NCRS Top Flight 2010 & 2018, 2003 Anniversary Red Convertible (sold) |
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#5 |
![]() Join Date: Mar 2023
Location: PA
Posts: 61
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I just did my 88 I did the ne compressor last yr in my 90 zr1 also. The compressor wont kick in with too low freon plus as you add it the sensor has the compressor kick on and off frequently as you add freon it slow down. I too had leaks as my 88 is a Challenge car and the ac has not been used in a long time. We found 2 leaks 1 was the Schrader valve itself. The other was the top aluminum supply to the firewall. The O ring was deteriorated . So now I am checking weekly to see if we got them all.
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#6 |
![]() Join Date: Dec 2005
Location: Delanson, NY
Posts: 911
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I tried to charge the system using the FSM procedure, no luck. Unfortunately there is no one locally which can work on a R12 car, good old NYS has banned R12 Freon and gives heavy fines to mechanics who use R12. So it looks like I will have to go the R134 conversion route.
I have a local shop which will do the conversion early next month. So much for keeping the car all original.
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1968 convertible Lemans Blue, 1986 coupe Medium Blue NCRS Top Flight (sold), 1990 ZR1 #2529 Red NCRS Regional and National Top Flight (sold), 1990 ZR1 #2124 Charcoal Metallic NCRS Top Flight 2010 & 2018, 2003 Anniversary Red Convertible (sold) |
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#7 |
![]() Join Date: Apr 2007
Location: Lake Bluff, IL
Posts: 2,063
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I had Marc Haibeck convert my'93 to R134 many years ago. He said, per GM's directive, no A/C equipment had to be changed, just change to fittings and fully evacuate the system. You might check with him on how to do it. --Bob
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2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough" |
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#8 |
![]() Join Date: Jan 2010
Location: Mystic CT
Posts: 2,619
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John
"What we have here is a failure to communicate" Just sent ya a text, maybe that'll work? Doug |
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#9 | |
![]() Join Date: Dec 2005
Location: Delanson, NY
Posts: 911
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John
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1968 convertible Lemans Blue, 1986 coupe Medium Blue NCRS Top Flight (sold), 1990 ZR1 #2529 Red NCRS Regional and National Top Flight (sold), 1990 ZR1 #2124 Charcoal Metallic NCRS Top Flight 2010 & 2018, 2003 Anniversary Red Convertible (sold) |
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#10 |
![]() Join Date: Sep 2016
Location: Ocala, FL
Posts: 889
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There are kits out there.
New compressor New dryer New expansion valve New Schroeder valves and O rings throughout. All lines and condensor and evaporator have to be thoroughly flushed because R12 oil and R134 are not compatable. Who do you trust to remove the plenum?
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