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How to DIY filling A/C?

Discussion in '308/328' started by Martin308GTB, Nov 16, 2020.

  1. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
    Full Name:
    Martin N.
    Hello from Germany,

    I am tired of the costs for a A/C refill with R134a over here. Secondly I had a bad problem with my compressor one year ago. The new York compressor leaked after just 12 months. So I installed a new seal and hope, that it's tight now. Now I would have to fill the system again. If something goes wrong further €s are gone.

    Now I noticed, that R134a refrigerant is quite cheap at the moment and I could purchase a 12kgs bottle for €160.00 (a 800g refill at the workshop is 120.00).
    Over here most folks vote against any DIY methods for filling the A/C. But since I heard, that it's nothing unusual in the United States I just want to begin with a stupid question:
    What equipment do I need to fill my A/C myself. I would purchase the above mentioned bottle and I have a vacuum pump.
    What other things do I need. And of course I will appreciate any directions for performing this task. Or hints or warnings :)
    I am still a bit hesitating, but like some of you know, I am a mechanical engineer and think I have performed much more dangerous things in the past, which were not just my private affairs :)

    Best Regards and thank you in advance
    Martin
     
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  3. mike32

    mike32 F1 Rookie

    May 13, 2016
    3,183
    Uk
    Does your system have any flex hoses and if so have the originals been changed for those that will handle R134
     
  4. ferrariowner

    ferrariowner Formula Junior

    Feb 21, 2014
    761
    Mansfield, TX
    Full Name:
    Ron
    Martin,
    A couple of thoughts below.

    Did you change your hoses? The original hoses will leak R-134.
    Replace all of the o-rings with green type.
    You need a set of refrigeration gauges
    Vacuum pump the system and make sure it holds a vacuum
    Refill the low pressure side with R-134. Use less R-134 than R-12 I think about 10-20% less R-134a (You can overfill the system).
    There is also a different expansion valve from R12 to R-134.

    Everything can be done yourself with a little knowledge and a few tools
    In the US we can purchase small cans of R-134 for a few dollars. Need 1Kg or less.
     
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  5. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
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    Martin N.
    Thanks so far.
    When I converted to R134a I emptied the condenser from the old R12 oil as much as possible. I also had the evaporator out. Mainly because I wanted to repair a crack in the plastic housing which caused ice cold water dripping onto the feet of my passengers. I replaced the expansion valve and the low pressure switch and all the O-rings with the green stuff. Then I had the system flushed with nitrogen and installed a new dryer.
    The system holds vacuum for hours.
    What I did NOT was replacing the hoses. But if I manage to perform a refill myself after purchasing 12kgs of refrigerant I wouldn't care about topping up a few grams regularly (each year or so).
    Could you give me further hints regarding the refrigeration gauges? Sources for kits including all adapters and hoses?
    I imagine, that theses have to be of high quality to avoid any havoc.

    Best from Germany and thanks in advance
    Martin
     
  6. ferrariowner

    ferrariowner Formula Junior

    Feb 21, 2014
    761
    Mansfield, TX
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    Ron
    Martin,
    Here is a link to a set of gauges from Amazon. It should have all the fittings needed for R-134a. I suspect you have the R-134a fittings installed on your existing system. There are a lot of sources for gauges. I am not familiar with any restrictions in your area. Hope this helps.


    https://www.amazon.com/JIFETOR-Manifold-Diagnostic-Household-Refrigerant/dp/B08CN2K19W/ref=asc_df_B08CN2K19W/?tag=hyprod-20&linkCode=df0&hvadid=459657529872&hvpos=&hvnetw=g&hvrand=4868723338850068190&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027230&hvtargid=pla-971045532692&psc=1
     
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  8. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
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    Martin N.
    Thanks Ron. This definitely helps. Once again A/C equipment is siginificantly cheaper in the US, than over here. Even including shipping costs and import tax.
    Restrictions: I think we have the most stringent restrictions regarding the handling of refrigerants. Don't tell anyone :) I don't care any more, since it's a lobby affair which involves the european parliament.
    At least refrigerant is quite cheap at the moment given the fact, that last year 12kgs would have been €400.00 +

    Best from Germany
    Martin
     
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  9. moysiuan

    moysiuan Formula 3
    Silver Subscribed

    Nov 1, 2005
    2,063
    Canada
    The 134 will leak out of the hoses, probably half a can of 134 each year to keep it topped up. But the system will work fine with 134, just not as cold as with R12 but still cold enough in all but the really hot climates where even the r12 system would struggle. Does anyone make a "kit" to replace the hoses with correct barrier hoses, complete with the OEM fittings on them? Most seem to have to custom make hoses which reuse their old fittings?
     
  10. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Martin. You will need a cross over fitting on the 12kg bottle of 134a. Remember that. I struggled a bit to find one but finally managed to find one on ebay as I remember it.

    Best, Peter
     
  11. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
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    Martin N.
    Sorry for stupid questions. But what's a cross over fitting? How does it look like?

    Best
    Martin
     
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  13. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,161
    California SF area
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    Paul
    Replacing the hoses will require removal of the right side fuel tank and you'll have to put the fittings on one end after they are run in the car so you'll need the tool for that. All of the hoses and fittings can be purchased on line and in fact you can get what is called "reduced barrier" hose which are the same ID but smaller OD which makes them much easier to route and deal with in general. Here in the U.S. you can buy cans of 134a with fittings and if you have a completely evacuated system you could just fill it by weight but otherwise you'll need a gauge set to do it properly. If you do not replace the hoses then you'll need the gauges to properly top it off seasonally.

    Also when you converted from R12 to 134a you should have changed the mineral oil with PAG oil because mineral oil and 134a don't mix.
     
  14. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
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    Martin N.
    This is the reason, why I didn't perform the job yet.

    Yes. Like said in my initial post I removed as much as possible of the old oil from the big bits like condenser and evaporator and had the system flushed afterwards. And of course the new T/CCI compressor was filled with the correct amount of PAG46.
    I would still love to know, why the seal of the brandnew compressor failed overnight after the system worked perfectly for nine months. (one morning I found a big puddle of compressor oil under the car and all the refrigerant was in the atmosphere). I reported in a former thread around christmas 2019.
    O.k. I will never know. FChatter crowndog -too bad he sold his 308- thankfully sent me a T/CCI seal kit I installed during the first months this year. Due to Covid-19 circumstances I wasn't able to have my system refilled yet and now I have decided to do it myself given the current low costs of refrigerant.
    Another reason. The condenser of my daily driver is somehow shot -not leaking, but loose fins- and the A/C performed poorly during this year's summer though A/C maintenance at my dealer showed only little loss of refrigerant over 7 years. With my own A/C equipment and the experience I will gain with all your help :) I can repair my daily driver's A/C as well.

    Best from Germany
    Martin
     
  15. Brian A

    Brian A Formula 3

    Dec 21, 2012
    2,353
    SanFrancisco BayArea
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    1983 US 308 GTS QV
    I highly recommend the book "Just Needs a Recharge: The Hack Mechanic Guide to Vintage Air Conditioning" by Rob Siegel. It is available from Amazon. It is an excellent guide that covers all the issues with vintage a/c. Frankly, you'll find that it is not just hooking up the gauge set and loading in the R134a but the book guides you through all aspects you'll need to consider. (... I suppose I have to do the full disclosure thing: I know Rob.)

    You will have no trouble refurbishing your a/c yourself. It's a pretty straightforward system. I have redone the a/c on my 1987 BMW 325ic and on my 1983 308 GTS QV. The BMW was a horrible job and the Ferrari was much more straight forward. The difference being that the Ferrari a/c components were all accessible from the front trunk while the BMWs components were all buried deep under the dashboard.
     
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  16. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    2,884
    Tallahassee, FL
    Martin,

    What is the local cost of servicing/refilling with r134? In the states, it's around $65 USD... so, just curious - as it's something that over here, is basically not economical for DIY.

    (I've no practical advice to offer, as I use a professional HVAC system to recharge mine. Fairly sure that's outside of your budget. ;) )
     
  17. maurice70

    maurice70 F1 Rookie

    Jan 25, 2004
    3,988
    Sydney
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    maurice T
    As others have mentioned, you will need a set of refrigeration gauges (Pretty cheap on Ebay for around $40),
    a Vacuum pump which you already have, a digital set of scales which will help you weigh in your refrigerant and the Refrigerant which you already know where to get.

    If you are confident that you don’t have any leaks,
    Connect the gauges to the High and Low side.
    Evacuate all the air/moisture out of the system with a Vacuum pump, this will generally take approximately 1 hr.
    Switch the Vacuum pump off and hold the Vacuum for a further 30mins.
    Weigh your Refrigerant bottle and take note of the weight..

    With your gauges still shut, remove the hose connected to the Vacuum pump and connect it to your Refrigerant bottle.
    Open the Valve on your refrigerant bottle and loosen the hose connection slightly where the charging hose meets your gauges and purge any air in the line, this usually doesn’t take more than a couple of seconds. Then
    re tightened the hose connection.
    Place the bottle on the scales and take note of the weight once again.
    You are now ready to begin charging the system.
    This is my method..

    Invert the refrigerant bottle and open the discharge/High side of the gauges and Liquid charge the system until your scales read approximately 750-800grams less than when you started. The system holds 1Kg and R134a usually requires 80% of the R12 charge.
    Some Refrigerant Bottles have a Vapour and Liquid port, If your bottle only has the one port, it will be a Vapour port which requires the above bottle inversion. If it does have a Liquid port, then connect the hose to that port and the bottle will not require inversion.
    Once you have reached that 750-800grams target, immediately close the discharge/high side gauge.

    Warning! Don’t Liquid charge through the Suction/Low side as this could lead to compressor damage.

    Check the usual connections to see or hear for any leaks.
    Start the car and turn the A/C on with the thermostat at its lowest setting.
    Keep the engine revs at around 2000RPM and check your gauge readings.

    Low side should be approximately 200 Kpa
    High Side should be approximately 850 Kpa
    These readings are taken at approximately 22Deg C ambient.
    If you are doing this on a hot day, try doing it in the shade or with a fan running across the Condenser.
    The above pressures will raise slightly depending on a higher ambient pressure.

    With R134a on my GT4 I was able to achieve 8-10 DegC vent temperature..

    With R12 as a comparison, I was able to achieve between 4-5 DegC

    Hope this helps.
     
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  18. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    5,611
    TX//Mexico/UK
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    Mike 996
    "I would still love to know, why the seal of the brandnew compressor failed overnight after the system worked perfectly for nine months. (one morning I found a big puddle of compressor oil under the car and all the refrigerant was in the atmosphere)."

    Had you been using the system regularly? One of the most common causes for seal failure is lack of use. Obviously, some seals are of better quality than others. Was the compressor you installed a brand-name or a knock-off?

    You should have a good set of gauges/a vacuum pump if you plan to do your own work. However, the best way to fill a system is by evacuating it/filling by weight. If you are not using R12, be sure to convert the weight of the original R12 to the equivalent weight of R134 (or whatever refrigerant). Of course, evacuating/refilling every time you need to "top off" is a PITA. However, with new hoses/seals, and a good compressor, etc, you should not have to refill...at least for a long time. It is NOT normal for AC systems to need periodic 'topping up.' We currently have a 17 year old car that has never had AC service and it can still freeze you out on a 100F+ Texas day! Basically, a "new" AC system requires no maintenance other than routine drive belt adjustment/changes but it should be operated regularly. Nothing is worse for mechanical devices than not using them!
     
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  19. maurice70

    maurice70 F1 Rookie

    Jan 25, 2004
    3,988
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    maurice T
    PS: Here in Australia, an individual requires a Refrigerant Trading Authority in order to buy any refrigerant, no matter the amount purchased.
    Only Licensed Refrigeration Technicians can handle refrigerants and major fines apply.
    R134a also wholesales at approximately twice of what you can buy that bottle for.
     
  20. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
    Black Forest Germany
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    Martin N.
    #17 Martin308GTB, Nov 17, 2020
    Last edited: Nov 17, 2020
    These are great hints. Thank you guys.

    Just ordered. It's even available on amazon Germany, delivered next day.


    With today's currency conversion around $120...150.00.

    Every few weeks, but then after two months since the last drive the seal literally blew over night during hibernation.

    T/CCI supplied by a specialized A/C shop in Berlin/Germany.

    @maurice70;
    thanks for your thorough directions. I know, that Oz is even more stringent than Europe. But like mentioned further above, it's just a
    lobby affair.

    Best from Germany
    Martin
     
  21. pshoejberg

    pshoejberg Formula 3
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    Dec 22, 2007
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    Martin, see complete shopping list for what you need in your PM box....-:) Prices and vendors included

    Best, Peter
     
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  22. Freddie328

    Freddie328 Karting

    Jul 29, 2013
    192
    Herts, UK
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    Richard
    Martin , if your car is still using a receiver/dryer as per original spec it will have a sight glass on the top. This is a good charging aid. It tells you whether the liquid line (that feeds the expansion valve) is actually full of liquid. After vacuuming the system you slowly add refrigerant through the service pressure gauge manifold until the sight glass is clear of bubbles/frothing (with the A/C running), and if charging on a cold day add an extra 50gms to compensate for warmer weather. Then you know the refrigerant charge is correct for R134a. It is important to have this sight glass clear, otherwise the expansion valve wont work so well. It needs feeding with liquid, not a mixture of liquid and gas. For future topping up, you can also also use this method.
     
  23. mike996

    mike996 F1 Veteran

    Jun 14, 2008
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    Mike 996
    Sight glasses were developed for use with R12. They are not reliable with R134 which is the reason sight glasses were eliminated from OEM AC systems when 134 became the "standard" refrigerant. Weight is the only accurate means of determining refrigerant charge. 134 can show bubbles/foam in a sight glass even though the charge is correct. In that case, filling until the bubbles/foam disappears can overcharge the system. Overcharging is worse than undercharging as far as system efficiency and strain on the compressor is concerned.
     
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  24. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,125
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    Martin N.
    That's so great! Thank you. More later this evening.

    That's what I understood, when the workshop explained me, why the refrigerant continues bubbling inside the dryer, though the correct amount of R134a -20% less in weight, than R12- was present.
    The new dryer came from FerrariUK (Maranello Concessionaires) and even wasn't expensive back then. Though coming inside a yellow box with horseys :)
    But it still didn't fit out of the box. I had to carefully remove a welded bracket. Otherwise it would have collided with the front trunk cover molding.

    Best from Germany
    Martin
     
  25. thorn

    thorn F1 Rookie
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    Aug 7, 2012
    2,884
    Tallahassee, FL
    I agree with Mike. I refill R134 in the Ferrari (and everything else, actually) by weight.
     
  26. Milkshaker0007

    Milkshaker0007 Formula Junior

    Sep 22, 2012
    336
    Midlands,uk
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    Paul
    interesting thread Martin,

    my brother in law does mine at his garage (refill that is only)

    i think this year (my 328) with the conversion rate from r12 to R134 we actually put in 600gms which was still blowing out nice and cold air, my BL worked it out on his phone and said next year will will put in 680 grams of R134 refrigerate as this is what the conversion from using old R12 to R134 told him on his APP.
    We added UV leak fluid and Oil to the system, and i still have NOT found any leaks to joints using my UV touch, so pleased overall with pressure and cold air outputted.

    would be nice to know from another 328 owner if this was correct for next year as planning on fitting a new dyer as 3 years old now.
    so we can Vac out all the coolant and measure how much has leaked naturally through the rubber pipes and pump into the system up to 680 grams back in.

    Is 680 grams on a 328 using R134 the correct amount????
     
  27. Brian A

    Brian A Formula 3

    Dec 21, 2012
    2,353
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    1983 US 308 GTS QV
    I think this is an important point and why simple recharging is not the solution. That is why Rob Siegel titled his book "Just Needs a Recharge". It is humor. To do it right, it never just needs a recharge. System integrity must be restored first. Both R12 and R134a are nasty chemicals; both are greenhouse gases and R12 is also an ozone depleter.
     
  28. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
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    Martin N.
    #25 Martin308GTB, Nov 17, 2020
    Last edited: Nov 17, 2020
    Honestly said, I know so many folks with classic cars -mainly luxury sedans-, who have converted from R12 to R134a and don't have to top up much periodically. If at all. Even with the old original hoses That said, I somehow doubt, that the system loses something like half of its amount during one year through the hoses. In such cases I suspect further leaks.
    And manufacturers still claim that an annual loss of up to 15% annually is still normal.
    Maybe the long hoses on the 308 make things worse. I will see. If it's really that bad I can still replace the hoses. 12kgs of refrigerant is more than enough material for years to come.
    That's another motivation: With my own equipment and skills I have to learn, I hope , that I can handle the topic A/C and its components more relaxed in the future.

    Best from Germany
    Martin
     
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