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328 a/c new compressor headache

Discussion in '308/328' started by schiconst, Jul 27, 2010.

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  1. schiconst

    schiconst Rookie

    Jun 16, 2010
    4
    #1 schiconst, Jul 27, 2010
    Hi. I've had an ongoing project with my 328 a/c. It stopped working about 2 years ago, so we did an r12 recharge. That didn't work, so I just drove it on nice days. Well, here in Florida nice (not scorching) days are few and far between, so I jumped into it last week. Based on the stickies, I purchased a new York compressor from Napa, new txv and drier. I went the r134a route, so I pulled every component and hose and did a chemical flush on it, removing all the old mineral oil and trash.

    Based on the instructions on the new compressor and factory 11 oz specs, I put 6 oz of POE in the compressor suction port, and 5 oz in the drier and lines.

    I got it all back together yesterday and ran the vacuum pump on it overnight, popped it off and it held 27 in for a few hours, so I figured I was good to go, right?

    Wrong. I connected my first can of r134a, opened the valve, and turned the car on. I jumped the LPS to engage the compressor. Suction is sitting at 110psi. Discharge is at 50psi. It doesn't seem to be pulling anything out of the can.

    My thoughts are defective txv (stuck open), or bad reed valves in the compressor (ugh...). Any ideas from the a/c experts??

    Thanks!

    John
     
  2. sowest

    sowest Formula Junior

    Aug 18, 2006
    899
    #2 sowest, Jul 27, 2010
    I am trying to think of some reason that would explain how you could get a higher pressure on the suction side than the discharge side: a mix-up in your message? A mix-up in the gauge connections?

    When I do this kind of work, I don't jump the low pressure switch. I introduce freon until the switch closes normally. I am guessing that you are using the small can of freon that is available at the normal parts outlets and not the 30lb tank. It may be that a single small can will not raise the pressure in a fully evacuated system to close the switch and make the system even marginally functional.
     
  3. schiconst

    schiconst Rookie

    Jun 16, 2010
    4
    #3 schiconst, Jul 27, 2010
    You're not misreading it. Blue on suction, red on discharge. I've checked connections, gauges (brand new, put them on another car and they read properly), everything. I am completely stumped.
     
  4. sowest

    sowest Formula Junior

    Aug 18, 2006
    899
    #4 sowest, Jul 27, 2010
    Hmm. Interesting. Are these readings with both gauge manifold valves closed?
     
  5. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,367
    NY
    #5 Steve King, Jul 27, 2010
    If you were holding 27" vacuum on the gage all you would do for the 1st can of freon is to attach it and open the can. It should suck down most of the can if not all of it. Then I would start the car and jumper out the LPS . Also get a pan of hot water and put the freon can in it as it fills. Run the engine up to around 1500-2000 rpm and put a house fan in the front of the radiator. You should fill the system to 80% of the old r12 capacity . Recheck the low pressure gage and keep it in the 35psi range . With 1 can in you should not see 110 psi on the suction side. Usually a high pressure reading on the suction line with a low pressure reading on the discharge line indicates a faulty compressor or stuck reed valves in the compressor head. Did you buy a rebuilt york compressor or a new one.
     
  6. sowest

    sowest Formula Junior

    Aug 18, 2006
    899
    #6 sowest, Jul 28, 2010
    Steve has given some good advice. I also share what I perceive as his being skeptical about rebuilt compressors.

    Another thought. The York compressors were made in both right hand and left hand suction. Could it be that the Roto-Lock fittings are on a compressor that has the head ports reversed?
     
  7. maurice70

    maurice70 F1 Rookie

    Jan 25, 2004
    4,334
    Sydney
    Full Name:
    maurice T
    #7 maurice70, Jul 28, 2010
    definately sounds like faulty reed valves in the compressor....If the tx valve was faulty you would be pumping the system down,,,meaning that the low side would start to drop in pressure..Do US 328's have York compressors??
     
  8. schiconst

    schiconst Rookie

    Jun 16, 2010
    4
    #8 schiconst, Jul 28, 2010
    Thanks for all the advice. I figured it out...it's always the little stuff. The suction r134a conversion fitting that goes on the factory r12 fitting on the compressor had some kind of small cap inside it that was completely closing off the suction side. The 110-120 lbs was the can pressure. Once I got the fitting sorted out, it took 3 cans and blows about 50 degrees. Thanks again.
     
  9. BigTex

    BigTex Seven Time F1 World Champ
    Owner Rossa Subscribed

    Dec 6, 2002
    79,406
    Houston, Texas
    Full Name:
    Bubba
    #9 BigTex, Jul 28, 2010
    I think all the new York compressors are gone....rebuilt is the only option....

    Great news you found the issue!
     
  10. schiconst

    schiconst Rookie

    Jun 16, 2010
    4
    #10 schiconst, Jul 28, 2010
    You can still get the brand new ones from NAPA. It was ~$360. The rebuild was ~$200ish. Thanks!
     
  11. Lawrence Coppari

    Lawrence Coppari Formula 3

    Apr 29, 2002
    2,192
    Kingsport, TN
    Full Name:
    Lawrence A. Coppari
    #11 Lawrence Coppari, Jul 29, 2010
    I charged my 328 last week with a new hose. At first it would not take the refrigerant but would release it through the hose if I loosened the fitting at the can end. It turned out that the screw on fitting was not depressing the compressor valve stem sufficiently for the refrigerant to flow into the system. In my case I only had to trim the little rubber seal inside the screw on fitting so that the fitting would screw on further and depress the valve stem more. The seal was merely a short piece of rubber tubing so I trimmed it about 1/32" with a razor blade. Strange thing about it, the hose worked on two other vehicles I have but not the 328. I guess they are 'special'.

    No problem charging now.
     

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