Subject: Re: automotive air conditioner The archived message # 4007 on converting to R134a. is attatched. It should be helpful. _____ Leon we eliminate the receiver-dryer/ accumulator that Elmo mentions (behind the passenger seat in the Flare. We use NAPA # 201091 fitting plus 2 o'rings (green). If you added a second rec-drier you need to get rid of that old R-12 rec-drier. 8 oz PAG oil and 2.8# 134a is what we use with our system. We get incredible cooling with the Chrysler 134a compressor and condenser mated to the Renault evaporator. Too much 134a will result in poor cooling as mentioned below. Greg Erickson Specialized Auto Inc. Bozeman, MT www.sworksrv.com cornerguy@sworksrv.com In front of the right side back passenger seat in the "flare-out" area, there is a removable panel with the receiver with an old fashioned sight glass on my 88 gas unit. As I recall from 40 years ago, add until the bubbles go away and the rest of the can. Probably not exact but the space in the receiver will probably accomodate at least a full can. If you are using a full set of gauges, add until the pressures stabalize on a hot day. What pressure readings are you using. I do not have a set of gauges calibrated for 134 so cannot help. When using F-12 long ago, you could normally get it to a point where the suction side corresponded to about the freezing point of the 12. With much less than that you would get coil freezup. If you already have charged the unit, and there are no bubbles in the sight glass, you probably have AT LEAST enough and hopefully not too much. If it sounds like the compressor is knocking, probably too much. Hopefully you had the equipment to pull a good vacuum or at least purged the unit with 134A after blowing it out with shop air. In the 60's, there was an outfit called "Comfy-Kit" that sold add on units and the procedure was to purge with one can, then add two cans for a unit with only one evaporator and short hoses. Four cans sounds like maybe a lot. --- In 1winne_h-bodys@y..., "Buddy Martin" wrote: > Hi everyone, > > I just converted my dash air unit in my 1989 LS 2.2 Gas from R12 to > R134A. When I got it the line to the evaporator was broken and I got > a new one made for $50 and put a new dryer/accumulator on it. I > flushed out all the lines and blew everything out with shop air. > Here is my question... I couldn't find out anywhere in the manuals > that states the capacity of the system as far as freon or oil. > www.sanden.com has a great manual for servicing the SD709 conpressor > and explicit directions for the R134A retrofit. It says that the > compressor is to be charged with 4.6 oz. PAG oil but of course > doesn't take into account the rest of the system. I put in a 8 1/2 > oz. oil charge that also had a o-ring conditioner built in and four > pounds of R134A. This got me down to about 58-62 degrees but > according to the pressure readings, I still don't seem to have enough > freon in the system. Does anyone know what is called for as far as a > full charge? > > Thanks, > Buddy > 89 LS --mpBQuNCFGkty4v54A3NXatK1Rg-GOEo6H90q-H8 Content-Type: text/html; charset=US-ASCII Content-Transfer-Encoding: 7bit On our Chrysler converted LeSharos we eliminate the receiver-dryer/
accumulator that Elmo mentions (behind the passenger seat in the Flare. We
use NAPA # 201091 fitting plus 2 o'rings (green). If you added a second
rec-drier you need to get rid of that old R-12 rec-drier.
8 oz PAG oil and 2.8# 134a is what we use with our system. We get incredible
cooling with the Chrysler 134a compressor and condenser mated to the Renault
evaporator. Too much 134a will result in poor cooling as mentioned below.

HTH

Greg

Greg Erickson
Specialized Auto Inc.
Bozeman, MT
www.sworksrv.com
cornerguy@sworksrv.com



In front of the right side back passenger seat in the "flare-out"
area, there is a removable panel with the receiver with an old
fashioned sight glass on my 88 gas unit.  As I recall from 40 years
ago, add until the bubbles go away and the rest of the can.  Probably
not exact but the space in the receiver will probably accomodate at
least a full can.  If you are using a full set of gauges, add until
the pressures stabalize on a hot day.  What pressure readings are you
using.  I do not have a set of gauges calibrated for 134 so cannot
help.  When using F-12 long ago, you could normally get it to a point
where the suction side corresponded to about the freezing point of
the 12.  With much less than that you would get coil freezup.  If you
already have charged the unit, and there are no bubbles in the sight
glass, you probably have AT LEAST enough and hopefully not too much.
If it sounds like the compressor is knocking, probably too much.
Hopefully you had the equipment to pull a good vacuum or at least
purged the unit with 134A after blowing it out with shop air.  In the
60's, there was an outfit called "Comfy-Kit" that sold add on units
and the procedure was to purge with one can, then add two cans for a
unit with only one evaporator and short hoses.  Four cans sounds like
maybe a lot.


--- In 1winne_h-bodys@y..., "Buddy Martin" <martin_w@p...> wrote:
> Hi everyone,
>
> I just converted my dash air unit in my 1989 LS 2.2 Gas from R12 to
> R134A.  When I got it the line to the evaporator was broken and I
got
> a new one made for $50 and put a new dryer/accumulator on it.  I
> flushed out all the lines and blew everything out with shop air.
> Here is my question...  I couldn't find out anywhere in the manuals
> that states the capacity of the system as far as freon or oil.
> www.sanden.com has a great manual for servicing the SD709
conpressor
> and explicit directions for the R134A retrofit.  It says that the
> compressor is to be charged with 4.6 oz. PAG oil but of course
> doesn't take into account the rest of the system.  I put in a 8 1/2
> oz. oil charge that also had a o-ring conditioner built in and four
> pounds of R134A.  This got me down to about 58-62 degrees but
> according to the pressure readings, I still don't seem to have
enough
> freon in the system.  Does anyone know what is called for as far as
a
> full charge?
>
> Thanks,
> Buddy
> 89 LS
________________________________________________________________________ ________________________________________________________________________ Message: 10 Date: Thu, 1 Aug 2002 14:36:27 -0400 From: franwrw@juno.com Subject: Re: automotive air conditioner Ooops! 4007 was the original question on a.c.. 5025 5026 were included on my last post as attachments. They have good info on recharging and converting to R134a. Leon [This message contained attachments] ________________________________________________________________________ ________________________________________________________________________ Message: 11 Date: Thu, 1 Aug 2002 22:16:59 EDT From: ecmatth@aol.com Subject: Re: Cab A/C Old underdash auto AC's had a similar thermostat, usually with a rotating knob vs. the slide type handle. Also a refrigerator thermostat from a household refrigerator could be made to work if you don't mind it looking a little different. A piece of plastic could be screwed over that part of the black panel and a rotating thermostat installed. Paint the plastic black or cover with black electrical tape if you are not trying to stay "original". The element is probably inserted in the fins or placed next to the fins of the evaporator coil. The main purpose is to cycle the compressor off before the fins frost up and stop air flow. You may be able to just short around the thermostat and run the compressor as on mine, I don't think it would ever get cold enough to frost the fins. I have converted to R134A./ ________________________________________________________________________ ________________________________________________________________________ Message: 12 Date: Thu, 1 Aug 2002 22:25:27 EDT From: ecmatth@aol.com Subject: Re: automotive air conditioner As I recall, my 88 gas unit holds about 2 pounds. There is a panel in the "corner" behind the front passenger seat that can be removed with the 4 covered snap on buttons and screws that reveals the receiver and an old fashioned sight glass just like the 1960's there were in front of the radiator. I converted mine to R134A when I got it last year. I suspect it is not as effective as R12 as I only get 20 degrees of cooling (air temp in minus air temp out) with the blower on high and it will not cool even the front two seats if outside temperature is above mid 80's. I run the generator and roof air and the engine air and it is satisfactory only to maybe 95 degrees outside temperature, especially when driving into the afternoon sun. ________________________________________________________________________ ________________________________________________________________________ Posted by: "VB john" johnmarg@infionline.net johnmarg1000 Tue OctÊ31,Ê2006 12:42Êpm (PST) This message is to relate my experiences in resurrecting the cab air conditioner in my '87 LS, Mopar conversion. Although it addresses a hybrid system, the problems encountered are mostly generic so hopefully it can help others To begin, the AC had not worked in the LS since it came into my possession about 2 years ago plus the donor Chrysler I acquired had a system with no charge and on disassembly, I found evidence of leak detector dye. I note this as a way of saying that I began with a pile of questionable parts along with no knowledge of their history. By default, the compressor had to be the one from the Chrysler and since I was using the Mopar radiator, its mating condenser was also opted for. Both of these were 1996 lineage and thus suitable for R-134. The evaporator, again by default, had to be the original Winnebago so its design was for R-12. Since neither vehicle had a charge, I decided it would be prudent to test each major component for leakage so I made up some adaptors to connect a vacuum pump. The Mopar components both checked good but the contributions from theWinnie would not hold and turned out to be a faulty hose between the condenser and receiver/dryer. The check was first done from the engine compartment by plugging one hose and applying vacuum to the other which means that four hoses, the evaporator, and the receiver/dryer is tested as a unit. Since the unit was leaking, it had to be seperated into its individual parts to isolate the fault. I luckily found the first part I isolated to be the bad one After I found the leak, a new hose was fabricated with fittings to connect it directly to the condenser which eliminated an adaptor I had made to mate Mopar to Winnebago. After the above testing, the system was tied together using the existing o rings on the connectors and vacuum was again applied. It would pump down to about 20 inches and would not hold so I then replaced all o rings that had been disturbed after which it pumped down to about 27-1/2 inches and held overnight. Feeling that the system was now tight, I let the vacuum run for about 1-1/2 hours to purge as much moisture as possible and disconnected it, leaving the system in vacuum while I addressed other issues. From trouble shooting the AC about a year ago I knew the thermostat was inopperative and in fact had been gutted. I had acquired a replacement some time back from another lister so set about installing it. This involved dropping the overhead plastic "headliner" and while in the area, I found one of the blower motors not running. Everything now stopped while I went shopping for a replacement motor and looking for a receiver/dryer to replace the rusty hulk I found behind the right side vertical trim panel behind the door. The new motor required some modification to adapt it and the thermostat had to be rewired to be compatable with the Mopar compressor control and this consumed a day or so to accomplish. I also figured this to be a good time to install an overhead trip console that I had salvaged from the donor car and this also added another day. After getting the overhead back into a presentable appearance, I returned to the task of preparing the system for a charge. Since the system had been exposed to about half R-12 and half R-134 I tried to find a refrigerant that is compatable to both which led me to explore the hydrocarbon types. After finding none available locally and no local shops that were enlightened about it, I opted for a charge of R134. After consulting with a friend who is retired from a career of AC servicing, I set about the task. I first connected the guages and verified the system was still in vacuum after about a week of setting after which I replaced the receiver/dryer and the remaining old o rings. On the advice of my friend, I purged the system with nitrogen followed by a purge with a sacrificial can of R-134 to clear out the remaining nitrogen and again pumped the system for about 45 minutes with the vacuum pump. I then set about charging with the 134 using cans that are premixed with refrigerant and oil and after about 28 to 30 ounces, the outlet ducts were blowing about 35 degree air with an ambient temperature just under 60 degrees. That was about 2 weeks ago and the ducts are still blowing cold but the ambient temperatures have stayed below 70 degrees so there has been no "true" test of how it will perform during the dog days of summer but I am hoping for the best. The following is related to the Mopar hybrid only so is not relative to a generic description but I include it in the event some 'convertees' are reading this. The only head scratching problem encountered was with the Mopar compressor control. Mopar uses a sensor in the evaporator to turn the compressor off if freezing tries to occur. This is only addressed in the service manuals as being used with automatic temperature control which I could not utilize in my application. After being unable to activate the compressor clutch, I started digging deeper, first thinking my thermostat rewiring was faulty. I finally found an obscure sentence that said that evaporator temperature is checked by the computer any time that AC is commanded. I finally determined that the sensor is a thermister and not merely a switch so I had to back track to the donor car to find out what resistance is needed to trick the computer into thinking that all is well. A 10 Kohm resistor in the harness now causes the computer to think the evaporator is about 50 degrees and all works well. If I ever get into the overhead deep enough to access the evaporator, I may just incorporate the sensor as I think it is a good idea. These are the numbers of the parts I found as replacements for the blower and the receiver/dryer: Blower motor---Siemens VDO number PM393 Modification to the shafts is required and is described in an earlier message #3957 Receiver/dryer--- Factory Air #33326---Located at Advance Auto as SKU #3894282--Direct replacement. John ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________