AC Refrigerant Leak

Discussion in 'The BS Topic' started by GoldenOne7710, Oct 23, 2017.

  1. GoldenOne7710

    GoldenOne7710 Irrelevant Member Lifetime Gold Member

    Jun 23, 2004
    Athens, GA
    On the wife's car. 2007 Mazda 6 2.3L. Been chasing a freon leak for a while. Last time I charged it, I put dye in it to hopefully pinpoint the culprit. Around the expansion valve = clean. All around the compressor = clean. The service connections = clean. Every point where's there's a connection with an o-ring = clean.

    However, the hose on the high pressure side is coated with gunk. I noticed yeaterday while I was changing the oil/filter which puts this otherwise hidden hose in your face under the car. It's as if there's an oily substance catching and accumulating the road grime. It's not just a small area, it's 80% of the hose. Do these things fail in such a way that coolant/oil seep through the lining?
  2. Burd

    Burd Veteran Member Lifetime Gold Member

    Oct 6, 2011
    Best thing is add some dye, run it fir a few weeks then check with a black light. You will know where the leaks are.
  3. Knuckle Dragger

    Knuckle Dragger Administrator Staff Member Lifetime Gold Member

    Nov 2, 2002
    Waddell AZ
  4. GoldenOne7710

    GoldenOne7710 Irrelevant Member Lifetime Gold Member

    Jun 23, 2004
    Athens, GA
  5. ssupercoolss

    ssupercoolss Veteran Member

    Nov 3, 2015
    Did you run a blacklight over it? The trickiest part to check is the evap. This could show up at your vents if the leak is pretty decent.
  6. GoldenOne7710

    GoldenOne7710 Irrelevant Member Lifetime Gold Member

    Jun 23, 2004
    Athens, GA
    I ran a black light over it twice in the past. I've used dye in it twice...just never have seen where it's coming from. If it is seeping through the high pressure hose as I suspect, it would certainly explain why I've never seen it. #1 the hose isn't something easily seen from the engine bay looking down. I saw this on coincidence by being under the car with the skid plate removed. #2, I would think all the road grime is soaking up the dye if it's coming the the hose wall.

    A hose is only $ refrigerant. Have to change the hose and vacuum it down this coming weekend.
    Knuckle Dragger likes this.
  7. ol' grouch

    ol' grouch Veteran Member

    Jul 4, 2013
    Evansville, In.

    The number following the letter R indicates the size of the refrigerant molecule. Think metal gauge. The smaller the molecule, the bigger the number. R-12 wasn't too bad the the R-134 can ablate through the hose. Future refrigerant coming into use next year will be worse. Your hose has probably started seeping through the rubber. The leaks (there are probably many) are really small and the dye molecule may be too big to get through. Like another poster said, replacing the hose should take care of the leak.
  8. twozs

    twozs Veteran Member

    Aug 5, 1999
    hopewell jct ny
    i've seen refrigerant bubble right through a hose . i wouldn't keep pumping dye in it ... it sound like its had its fill .. 20 years of doing hvac work and never used dye . nitrogen and leak detector bubbles .unless you plan to flush it out .. because the hose is shot not " molicule size . some of the freons now ( like 134a ) is a azeotropic mix so ..
    Last edited: Oct 23, 2017

Share This Page