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  •  » AC questions Summer is coming

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    5/20/2013 8:44 PM  #1

    MarkinSC
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    AC questions Summer is coming

    Yes its a convertible fox, but my wife and co workers won't ride in a car without AC. Strange...but true.

    Last summer i installed the cheap r134 conversion kit, and I got the compressor to turn on, but it didnt last at all. I used the stuff with the dye in it, and didn't find a leak.  The liquid line was all rusted so I figured that was the problem.  I removed the liquid line, the accumulator with hose, and the other discharge hose. I ordered all new stock componets of those hoses, and bought a green seal kit to install on the compressor and on the evaporator to accumulator, and for the condensor.  I hardly heard a hiss when I took off the first hose connection. So the system isn't holding anything.

    My next plan was to get all new stock hoses and accumulator, throw in some pag oil,  blow compressed air thru my condensor and evaporator, replace black seals with green ones, tweak screw on switch  and just recharge with r134?  bad plan?  The vacuum thing is just to get rid of oils stuck in the system, right? Or does it suck all the air out too to make room for the freon?  

    The conversion kits for fox's to 134a run $600-900. Pretty steep.

    Are condensors specific for r12 vs 134a?   When I see the conversion kits, they seem to point out that the condensor is bigger for 134a.  What condensor are they using for thier kit? is it from another year mustang post fox era? or are they making a specific condensor for it? If I bought a new stock condensor, can I use it for 134a?  My condensor looks in good shape and I was going to try and reuse. 

    It seems the compressor in these kits are all Sanden HD715 model with special brackets to bolt on in place of the stock compressor.  They say this component makes the biggest difference when converting to r134a. But I also read that the stock compressor will work fine too as long as the black seals were replaced with green seals, and it was thoroughly emptied of all fluids, and switch was tweaked.   

    Also the hoses in these kits.  Are these aftermarket kits specifically making these hoses or are they using part numbers from other year mustangs / vehicles?  Some aftermarket kits do away with the spring lock connectors on the ends of the hoses.

      It seems that they mention the accumulater drier in these kits is made specifically with dessicant for r134.  If I get a new stock accumulator with hose, can i use r134 or is it only made for r12? 

    Those aftermarket kits also seem to have a special cut out switch built into the hose and wired in serial with the pressure switch and is a requirement for 134a?  CAn i get away without it?
     

    GET HER DONE BULLETBOB!!! ..
     

    5/20/2013 8:54 PM  #2

    josh-kebob
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    From: Madison, AL
    Registered: 4/06/2013
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    Re: AC questions Summer is coming

    Go to foxmustangrestoration.com...............look up their "complete" AC system.  It's around $500.
    Free shipping from NC.........

    I bought mine from them last year and changed "everything" in my Fox 'cause my compressor shelled and I wanted all new, clean, parts.

    It's now cooling nicely with a 134 charge......and has been for over a year.



     

    Last edited by josh-kebob (5/20/2013 8:57 PM)

     

    5/21/2013 11:53 AM  #3

    wsinsle
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    From: Belle Vernon, PA
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    Re: AC questions Summer is coming

    Mark I'm not an AC expert but I would say you should pull a vacuum before putting in Freon. When I hit a deer with my truck I had to replace some AC parts. I pulled vacuum with an air compressor and a cheep set up from Harbor Freight. I also bought a cheep set of gauges from there. Once you pull vacuum for several minutes, shut it off and verify it holds vacuum with gauges. That’s how to check for leaks before adding and wasting freon

    Last edited by wsinsle (5/21/2013 11:55 AM)

    If this forum can't fix it, it isn't broke.
     

    5/21/2013 1:31 PM  #4

    George
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    From: Central California
    Registered: 4/01/2013
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    Re: AC questions Summer is coming

    You must use the R134 barrier hoses. Replace the drier. You must pull a vacuum for 20 minutes and it must hold the vacuum. What the vacuum does, is boil out any moisture in the system. Add a can of PAG oil. And recharge with R134 to 80% of what the R12 system calls for. The added pressure switch should also be used. It is a high pressure cutout switch. R134 runs at a higher head pressure then R12 does.
    When the system is charged you should have approximately 250 psi on the high side and 20 psi on the low side.

    Cut to fit, Pound to shape, Paint to match
     

    5/21/2013 4:29 PM  #5

    midnite
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    Re: AC questions Summer is coming

    I would definitely get a shop to test the system, they can tell what may be wrong by the readings on the gauges as mentioned.

     

    5/21/2013 7:45 PM  #6

    MarkinSC
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    Re: AC questions Summer is coming

    George wrote:

    You must use the R134 barrier hoses. Replace the drier. You must pull a vacuum for 20 minutes and it must hold the vacuum. What the vacuum does, is boil out any moisture in the system. Add a can of PAG oil. And recharge with R134 to 80% of what the R12 system calls for. The added pressure switch should also be used. It is a high pressure cutout switch. R134 runs at a higher head pressure then R12 does.
    When the system is charged you should have approximately 250 psi on the high side and 20 psi on the low side.

    Just out curiosity then,  if the hoses are designed for R134 instead of R12,  then how is it that they sell those conversion kits at walmart, autozone, etc, and all they include are fittings that go over the existing fittings on the compressor ports and a special can of freon?  And there's no cutout switch either.  So if they are absolutely necessary, then how to do they sell those kits if those items need to be installed? They also make no mention in the kit that a new drier is needed either.  If I'm replacing all the hoses, why pull a vacuum to boil moisture? There would be no moisture in the new hoses and drier. I can see to pull vacuum to test for leaks. But is it important for the system to pull a vacuum for the freon gas to be sucked into the system?  The kits contend that as long as the system has not been "opened", no drier change is necessary, and no vacuuming either. The kit contains a moisture absorbant that absorbs all moisture in the system. The kit also contains oil in the r134 that is compatible with the oil that may already be in the system.  The kit r134 also has a sealant to seal leaks and a dye to help detect leaks.  OBVIOUSLY it didn't work for me last summer LOL. but i'm just curious LOL 

    GET HER DONE BULLETBOB!!! ..
       •Thread Starter
     

    5/21/2013 9:07 PM  #7

    George
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    From: Central California
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    Re: AC questions Summer is coming

    The kits that are sold to the public are retro conversion kits. The fittings convert r12 to r134 fittings. The R134 in R12 hoses will leak out. That is why the conversion kits are not being sold in many states.
    To do the conversion properly. You need to change the drier. More important if the system was opened for a hose change. You have to pull a vacuum to boil out the moisture. The air has moisture in it. You need to pull a vacuum if the system is compltely discharged, if the gas goes out, air will enter. If you simply charge the system with moisture, it will not cool. The drier does 2 jobs. It drys the R134 and filters the gas. I was just offering the proper way to convert the system to R134. The PAG oil mixes with mineral oil used in r12 systems. There is no special R134. There is R134 with dye added for leak detection. The adding a high cutout switch is required by law on a R134 conversion. The EPA also requires the special barrier hose. A commerical AC shop is required to do the upgrades upon a system conversion. A fly by night shop will do the wal mart conversion.

    Cut to fit, Pound to shape, Paint to match
     

    5/21/2013 9:11 PM  #8

    MarkinSC
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    Re: AC questions Summer is coming

    George wrote:

    The kits that are sold to the public are retro conversion kits. The fittings convert r12 to r134 fittings. The R134 in R12 hoses will leak out. That is why the conversion kits are not being sold in many states.
    To do the conversion properly. You need to change the drier. More important if the system was opened for a hose change. You have to pull a vacuum to boil out the moisture. The air has moisture in it. You need to pull a vacuum if the system is compltely discharged, if the gas goes out, air will enter. If you simply charge the system with moisture, it will not cool. The drier does 2 jobs. It drys the R134 and filters the gas. I was just offering the proper way to convert the system to R134. The PAG oil mixes with mineral oil used in r12 systems. There is no special R134. There is R134 with dye added for leak detection. The adding a high cutout switch is required by law on a R134 conversion. The EPA also requires the special barrier hose. A commerical AC shop is required to do the upgrades upon a system conversion. A fly by night shop will do the wal mart conversion.

    George, thanks for the replies.  I just ordered all stock hoses and drier. Does this mean I can't use the R134a?

    GET HER DONE BULLETBOB!!! ..
       •Thread Starter
     

    5/21/2013 9:30 PM  #9

    George
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    From: Central California
    Registered: 4/01/2013
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    Re: AC questions Summer is coming

    You should be ok with the new hoses. They should meet R134 specs. When installing the conversion fittings. The high side fitting that screws on has a valve core. You must remove the hose fitting valve core. Just don't stack valve cores. It will cause a leak. If you don't have the R134 gauges or vacuum pump buy the harbor freight stuff. If you have a compressor, You can also buy the cheap vacuum pump that runs on compressed air. It works very well.

    Cut to fit, Pound to shape, Paint to match
     

    5/22/2013 4:28 AM  #10

    MarkinSC
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    Re: AC questions Summer is coming

    George wrote:

    You should be ok with the new hoses. They should meet R134 specs. When installing the conversion fittings. The high side fitting that screws on has a valve core. You must remove the hose fitting valve core. Just don't stack valve cores. It will cause a leak. If you don't have the R134 gauges or vacuum pump buy the harbor freight stuff. If you have a compressor, You can also buy the cheap vacuum pump that runs on compressed air. It works very well.

    I installed those fittings last summer when i tried to use just the kit.  IIRC it just screwed on top of existing valve, i dont remember taking one off. ..  i have a compressor. I think i can rent pump and gauges at autozone.  i do have a harbor frieght store closeby.  i'll check it out.

    GET HER DONE BULLETBOB!!! ..
       •Thread Starter
     

     

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