AF: A/C problem - question | Page 2 | Allpar Forums
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

A/C problem - question

Discussion in '1995-2017 FWD Sedans, Coupes' started by captn, Aug 17, 2019.

  1. Dave Z

    Dave Z It's me, Dave
    Staff Member Level III Supporter

    Joined:
    Jan 23, 2001
    Messages:
    34,931
    Likes:
    20,610
    Ambient temperature and air pressure do alter the amount of pressure for the a/c system.

    I looked up the system and it looks like a poorly developed system I also have - https://amzn.to/2KUFz6g - bought it on a moment of weakness (for much less $). It's not really the right thing to do the job well, and I regret getting it (for something like $10 at some car parts store).

    If I wanted to really do it on the cheap I'd buy one of these, at least, which can use standard R134a cans ... https://amzn.to/33VXBg9

    A gizmo like this would be more appropriate... but still not ideal... Search Results For "a/c r134a manifold gauge set" (at https://www.harborfreight.com/search?q=a/c%20r134a%20manifold%20gauge%20set )

    Really, if you don't have a leak, just pay a pro $100 and get it over with. If you do have a leak, pay a pro to fix it or at least get the pro to evacuate the remaining refrigerant, then find and fix the leak, then pump out the system thoroughly and refill it.
     
  2. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    31,881
    Likes:
    5,195
    I invested $50 in that gauge set, and $100 for a vacuum pump probably 7 years ago, and have used it at least 1/2 dozen times. It still works great, and results are great. Not always the case with Harbor Freight, but this equipment can be trusted.
     
  3. Dave Z

    Dave Z It's me, Dave
    Staff Member Level III Supporter

    Joined:
    Jan 23, 2001
    Messages:
    34,931
    Likes:
    20,610
    Sometimes they have surprised me by having higher quality than expected. I think a better bet than Amazon's selection of “let's use an algorithm to create company names” Chinese manufacturers.

    I suspect most of us do not have your patience and skill for working with a/c. Certainly you've gotten your money's worth, probably the first time you used them.
     
    Bob Lincoln likes this.
  4. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    Thanks Bob, we will agree to disagree. How often do gauges fail, to me then renting a manifold set from say, AutoZone, your dealing with unknown gauges, who knows what idiot or not idiot used it last, was told by the AutoZone rep. that faults in equipment are sometimes not reported fear of not receiving there deposit back and they certainly don't check them. Anyway buying a new R134 top up kit and putting the new gauge on the LP side and registering low pressure then slowly bringing the pressure up to just in the green doesn't seem like a big issue to me.

    If you have a leak, go to a professional. Just talking about topping up the system.

    We should bring this to rest for others who want to top up there a/c systems, who read and who do understand the mechanics of what there doing and abide by the safety rules shouldn't have a problem doing this.

    Would like to hear from others that disagree with this.

    Regards.....
     
    #24 captn, Aug 27, 2019
    Last edited: Aug 27, 2019
  5. valiant67

    valiant67 ...

    Joined:
    Jan 7, 2003
    Messages:
    36,665
    Likes:
    19,407
    The simple fact is you can't know the health (and if you have a proper charge in the system) unless you are monitoring both high and low pressures.
    There is always a gamble if you are using a gauge on the can with nothing to monitor the high side pressure. Are you OK in most cases? Yes, but it's easy to avoid the gamble and monitor both.
     
    Bob Lincoln likes this.
  6. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    31,881
    Likes:
    5,195
    I don't consider a dial with red, yellow and green 'zones' with no numbers, to be a gauge. Nor did you state that you had a pressure vs temperature chart available. It's common, but it's a hack method that can damage the system. To me, if it's worth fixing at all, it's worth doing it right and not risking taking out the entire system for the sake of a cheap shortcut.
    Not to mention, if you've ever blown out a hose or the high pressure relief valve, you really don't want that experience. And then it requires a lot of money or professional intervention.
     
  7. andybuzz2u

    andybuzz2u Active Member

    Joined:
    Mar 23, 2004
    Messages:
    56
    Likes:
    7
    The air blend door actuator is out of sync, meaning it's dying a slow death. Remove the negative battery connection for five minutes are reinstall. Sometimes it works, sometimes you simply have to replace it. I agree with the other comments, without verifying system pressure, system charge level, and a bi-directional scanner to check codes and the actuators, blower motor, resister or module, it's all words. The A/C system wants 0.454 Kg(1.0Lb) of R134a, no more, no less. You can't hit that mark blindly adding freon from a can into a system with an unknown quantity to start with.
     
  8. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    Thanks Bob, It worked out perfectly, charged and worked fine till about a month ago. There must be a slow leak therefore added a green dye with a stop leak and recharged the system.

    AC worked but only out of the passenger side, feels like outside air blowing out of the drivers side, The odd thing here is over the winter I was mentioning hot air came out of the driver side ducts but only warm air out of the passenger side which I was unable to find the problem. Came to the common conclusion that the heater core could be partially blocked. I googled and watched a video of a shop replacing the core and it wasn't something I was getting into for obvious reasons. I can live with it, wife's not too happy.

    I must have a door issues regarding the AC and before I tear the car apart I need to identify the location of the blend door, which I don't have a knob to control. From what I've seen this knob would the in the center where mine is just the temp setting. AllenC above sent a link of a heater box that doesn't match mine. All the hvac controls operate correctly and do what there suppose to, directing the air to the correct ducts, temp adjustment and fan speed, this door must be doing it's own thing.

    Would really appreciate any suggestions, thank you.
     
  9. Dave Z

    Dave Z It's me, Dave
    Staff Member Level III Supporter

    Joined:
    Jan 23, 2001
    Messages:
    34,931
    Likes:
    20,610
    The green dye shows up really well when you use a blue light. They sell blue flashlights.

    FWIW, the most likely problem on an older car is the evaporator, if you can't find evidence of a leak anywhere else and the compressor has stopped going on (the car will not run the compressor if there is insufficient refrigerant).
     
  10. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    Thanks DaveZ, I didn't see any green dye residue but will look on Amazon for a blue light flashlight. The compressor has always ran once called for, connecting the gauge showed low pressure and only had to add little to get cold air.
    Cold only coming from passenger side has got me baffled.
     
  11. Dave Z

    Dave Z It's me, Dave
    Staff Member Level III Supporter

    Joined:
    Jan 23, 2001
    Messages:
    34,931
    Likes:
    20,610
    Better off with harbor freight etc..
     
  12. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    31,881
    Likes:
    5,195
    I think I bought my UV penlight and protective glasses at one of the parts stores, probably Advance Auto.
     
  13. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    When full evacuation and refill of the refrigerant is undertaken, having not replaced any components does the pag46 oil have to be re-added? Wondering when the evacuation process is undertaken whether it removes the oil?
     
  14. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    31,881
    Likes:
    5,195
    It does remove some oil, so you have to guess and add a little back. If there was no catastrophic leak or large oily stain anywhere in the system, I'd add back one ounce. Too much will reduce efficiency and harm the compressor (in large quantities). Too little will burn out the compressor.
     
  15. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    Borrowed set of gauges and vacuum pump and connected and was zero pressure in the system. Evacuated to 30 inHg and turned off pump, waited an hour and down to 18.

    Had originally used the green dye and have checked as much as I can and see nothing. Considering using a stop leak product before taking it to the shop. The quotes I've had from repair centers makes me consider going without.

    Any suggestions on using a stop leak and what product to use would be appreciated.

    Best regards,
     
  16. ImperialCrown

    ImperialCrown Moderator
    Level III Supporter

    Joined:
    Jun 8, 2008
    Messages:
    21,189
    Likes:
    4,389
    Do not use a stop-leak in the A/C system. Repair the leak properly.
    We had customer cars with stop-leak added that gummed up our shop refrigerant reclaiming/recharging machine to the cost of $8000. It had to be replaced at the height of the busy summer A/C repair season.
    It may be temping to use as a cheap Hail-Mary and it may not fix anything.
     
    Doug D, Bob Lincoln and AllanC like this.
  17. AllanC

    AllanC Well-Known Member

    Joined:
    Jan 6, 2003
    Messages:
    4,531
    Likes:
    1,122
    I would agree wholeheartedly with NOT using any kind of refrigerant stop leak on a system. No "MAGIC ELIXIR" will fix any mechanical abrasion, opening, solder joint fail in a system component. At most you will slow the leak but not fix it.

    If the evaporator is leaking use a refrigerant sniffer inserted through the lower HVAC plenum openings used for heat. Refrigerant is heavier than air and will tend to settle and escape in the plenum lower openings. Use dye in the refrigerant system along with special light to identify leaks in the under hood area plumbing.
     
    Bob Lincoln and ImperialCrown like this.
  18. Bob Lincoln

    Bob Lincoln "CHECK FAULT CODES"
    Level 2 Supporter

    Joined:
    Jul 10, 2002
    Messages:
    31,881
    Likes:
    5,195
    Agree with above - it will only clog the system and blow out the high-pressure relief valve.
    This is too large a leak to fix with any stop leak, if it dropped to 18 inches in one hour. A component or seal needs replacing. No way around it if you want your A/C to work.
     
    Doug D and ImperialCrown like this.
  19. captn

    captn Active Member

    Joined:
    Jan 10, 2003
    Messages:
    151
    Likes:
    9
    Thanks Bob, evacuated a few more times to get a better feeling and seems the last time I took it to 30 in and I left it for two hours and dropped 11, gauge read 19 ins. Used that green dye some time ago and am unable to see the leak anywhere, got under checked compressor area and followed the pipes as far as I could, the condenser etc. I ordered a sniffer as the only thing I'm afraid of if it's the evaperator. That is not a job I'm going to undertake, watched a youtube of a guy undertaking that job and the only thing he didn't remove was the muffler.
     
  20. Dave Z

    Dave Z It's me, Dave
    Staff Member Level III Supporter

    Joined:
    Jan 23, 2001
    Messages:
    34,931
    Likes:
    20,610
    Evaporator is a terrible job. Did it on a 300M and it cost $1200 at the dealer and they gave us whatever discounts they could. That said, we kept the car for another four years and were very happy with it.
     

Share This Page

Loading...
 We are not affiliated with FCA. We make no claims regarding validity or accuracy of information or advice. Copyright © VerticalScope Inc. All rights reserved.