D100 A/C R12 to 134a conversion. Q's and unknown part..
#1627603
06/02/14 03:51 AM
06/02/14 03:51 AM
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Joined: Oct 2013
Posts: 12 dfw, Tx
AJP087
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dfw, Tx
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Okay I have an 1989 3.9 v6, D100, that I'm trying to get the air conditioner working on, this next week. I have a good compressor for it (which was missing when I bought it) and everything else is there and looks okay.
I also bought a new gasket kit and dryer. Bought some gauges and a vacuum pump that works with an air compressor.
I still need r12 to 134a conversion fittings, and I guess to find a sticker?
I notice there is a pressure switch on the low side that is like a round plastic disc by the firewall. I was wondering if the pressures are different from the r12 to 134a and if I will need to replace that switch??? The only one I can find is a -all metal one, labeled 134a at the parts store.
Also there is this piece on the low side line that connects to the compressor. The piece is on a canister. I don't know wtf it is. It kinda looks like a sensor missing a wire connector, but I didn't find a wire that would connect there. Better yet, here is a picture.
When the a/c works on these trucks, is it very good? Worse with 134a or about the same?
Any suggestions?
I really do not want to spend another Texas summer without air conditioning, am kinda excited. Thanks.
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: AJP087]
#1627604
06/02/14 04:34 AM
06/02/14 04:34 AM
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Joined: Aug 2003
Posts: 12,291 Kent, Wa
340SHORTY
Truck Nut
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Truck Nut
Joined: Aug 2003
Posts: 12,291
Kent, Wa
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That piece is called a muffler. Besides changing the seals, a R134 system uses a condenser that flows better than the R 12 system. A R134 system uses a charge equal to about 2/3 3/4 of what a R12 system uses.
I am truckless..
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: 340SHORTY]
#1627605
06/02/14 03:30 PM
06/02/14 03:30 PM
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Joined: Oct 2013
Posts: 12 dfw, Tx
AJP087
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I looked up a new condenser, and its $150!! A/C for these trucks aren't cheap. Especially looking at what a new compressor and hoses go for! From the pics of a new condenser, I do see how the tubes are parallel, as opposed to series like the unit I have. Seems, it would flow a lot better. Is the muffler the piece hanging off the canister? Or the canister itself is called the muffler? If so, what is the piece that looks like a sensor? Thanks.
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: AJP087]
#1627606
06/02/14 04:36 PM
06/02/14 04:36 PM
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Joined: Jan 2003
Posts: 16,376
dogdays
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,376
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If the system still holds a little pressure you could top it off with some R134A after you added some Ester oil (works with both R12 and R134A).
At least that's what I did on an '89 Taurus, put in two or three little bottles of Ester, then about 2 1/2 bottles of R134A.
The pressure switch wouldn't let the compressor run so the oil and the first couple of bottlesof R134A, I put into the low pressure side using a heat gun on the bottle. At that point the compressor kicked on and I added the remainder of the R134A with engine running, A/C on high, windows open, and a thermometer stuck in the dash vent. When it got below 38 degrees F I stopped adding the R134A.
This is "ultimate shadetree" mechanicing at its finest, not very elegant, but that A/C system worked through three summers like that.
PAG oil will not work for R12, don't use it on a mixed system.
There isn't an A/C shop who will work on a mixed refrigerant system, at least not to my knowledge. That means once you step out over that edge you can't go back. My '89 I knew was never going to see the inside of a refrigeration shop so I had at it.
The books are full of warnings about condenser insufficiency and compressor failures, these MAY happen but they didn't happen to me. I didn't change one other part from what I wrote above, except adding the R134A port conversion fitting to the stock port.
R.
PS: I hear the price of recycled R12 is coming down as demand ges down. Or smuggle it in from Mexico.
PPS: There are Federal laws against these procedures, so I am expecting the FBI to be breaking down my door at any moment.
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: AJP087]
#1627608
06/03/14 03:21 PM
06/03/14 03:21 PM
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Joined: Jan 2003
Posts: 25,893 Rio Linda, CA
John_Kunkel
Too Many Posts
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Rio Linda, CA
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Ignore all the advice here and fix any leaks; then recharge with R-12.
The INTERNET, the MISinformation superhighway
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: John_Kunkel]
#1627609
06/03/14 03:50 PM
06/03/14 03:50 PM
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Joined: Jan 2003
Posts: 6,183 Bridgeport, WV
Michael
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Posts: 6,183
Bridgeport, WV
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Quote:
Ignore all the advice here and fix any leaks; then recharge with R-12.
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: AJP087]
#1627611
06/04/14 05:17 PM
06/04/14 05:17 PM
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Joined: Jan 2003
Posts: 25,893 Rio Linda, CA
John_Kunkel
Too Many Posts
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Posts: 25,893
Rio Linda, CA
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The hoses are often the weak link in old systems and they'll be much more so if converting to R-134. Good idea to have them rebuilt with barrier hose no matter which way you decide to go.
The INTERNET, the MISinformation superhighway
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: dodgedakotaman]
#1627613
06/05/14 12:46 PM
06/05/14 12:46 PM
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Joined: Jan 2003
Posts: 21,079 Niles , Ohio
therocks
oh wait.but hey.lets see.oh yeah.
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oh wait.but hey.lets see.oh yeah.
Joined: Jan 2003
Posts: 21,079
Niles , Ohio
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I did a bunch of swaps at work years ago.Most we used the old hoses if they were decent.I like to change the O rings to the new ones.That and you run less 134 than 12.IIRC it 80 or 85 % of factory spec.Most cooled as good as the 12 did.I used ester oil in most conversions.Just dont add too much as it will affect pressure and it wont cool.Rocky
Chrysler Firepower
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Re: D100 A/C R12 to 134a conversion. Q's and unknown part..
[Re: AJP087]
#1627619
06/07/14 05:39 PM
06/07/14 05:39 PM
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Joined: Jan 2003
Posts: 25,893 Rio Linda, CA
John_Kunkel
Too Many Posts
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Too Many Posts
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Posts: 25,893
Rio Linda, CA
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The factory V2 compressor has a plug in the sump that can be removed to check the oil level with a home-made dipstick. If you had the system open to replace the compressor there is no R12 remaining in the system but it's not the remaining refrigerant you need to worry about, it's the remaining mineral oil.
Ester oil will work with both R12 and R134.
The INTERNET, the MISinformation superhighway
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