Another AC thread | Page 2 | FerrariChat

Another AC thread

Discussion in '348/355' started by bayferrari, Aug 28, 2019.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

Page 2 of 2
  1. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #26 bayferrari, Sep 27, 2019
    Ok, so I pulled a vacuum on the system, held a good vacuum overnight, about 26 psi. Today I tried to fill the system again. With ac switched on system low side valve open, I got pressure up to about 70 psi, nothing on high side, turned ac system off, pressure on low side dropped to about 50 psi and high side came up to about 50 psi. Tried to charge more pressure into low side, with high side closed, pressure continued to rise on low side but no effect on high side pressure.. I think compressor kicked on for a moment in initial charge but shut off when I turned ac switch off. Never heard it cycle again. I have no evidence of bubbles in the sight glass on the receiver dryer. Could not hear condenser fan kick on either. Could I have a block in the condenser? Should I remove condenser lines and tried to blow thru it?
    Any help appreciated.
     
  2. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #27 m.stojanovic, Sep 27, 2019
    It looks like the compressor is pumping the wrong way. There are Sanden compressors that look the same as the 348's but are designed for engines with counterclockwise crankshaft rotation.
     
    Qavion likes this.
  3. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #28 bayferrari, Sep 28, 2019
    That's an interesting conclusion The part number I picked from the polar bear web sight said it was an exact replacement for the Ferrari part number.
     
  4. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #29 m.stojanovic, Sep 28, 2019
    Another possibility is that you have accidentally connected the hoses to the compressor the wrong way around. The picture of the 348 compressor I have shows that the suction and delivery ports (marked "S" and "D") are the same size so it seems possible to connect the hoses wrongly.
     
  5. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #30 bayferrari, Sep 28, 2019
    Maybe I did connect the lines to the compressor backwards? Does anyone off hand know if looking towards the front of the car the hose on the right of the compressor is low or high pressure?
    The hose on the left of the compressor is high or low pressure?
    I should be able to determine by the ac lines that connect to the engine bulkhead which is which. Where the hoses connect at the intermediate bulkhead are definitely different sizes. Large hose equals high pressure.
     
  6. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #31 m.stojanovic, Sep 29, 2019
    Larger hose (larger bulkhead fitting) is suction, i.e. low pressure. This should connect to the LEFT compressor port looking at the rear of the compressor (towards the front of the car).

    Image Unavailable, Please Login
     
  7. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #32 bayferrari, Sep 30, 2019
    Got it, hoses are connected properly. Compressor part number from Polar Bear is CO 7840F and CO 7840SAN.
    I'm stumped.
     
  8. Koenig1

    Koenig1 Formula Junior

    Aug 25, 2016
    328
    Ottawa ON
    Full Name:
    Sandy
    #33 Koenig1, Sep 30, 2019
    Last edited: Sep 30, 2019
    My compressor has exact same part# from Polar Bear, working fine in my 91 348TS. Your issue is probably somewhere else??? Unfortunately cannot help with AC.
    Quantity Item Code Description Price Each Amount
    1 1 CO 7840F SD7H15 5GR 12V CB 289.00 ....Compressor
    1 RD 6455 MIORxFIOR W M SP FERRA 42.50 .... Drier
    You state the compressor started up ONCE? Is the clutch actually engaging? Maybe unplug the pressure switch and jump the connection to see if compressor engages.... be careful... definitely something amiss... fuses all good???
     
  9. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #34 m.stojanovic, Sep 30, 2019
    If there is no problem with the compressor clutch engagement, you can check which way the compressor is pumping if you disconnect the hoses from it, close one port at a time with your thumb and rotate the compressor clockwise by had. You should feel quite a high pressure on one port and suction on the other. Are the ports marked "S" and "D" on your new compressor?
     
  10. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #35 m.stojanovic, Sep 30, 2019
    If everything is good with the hose connections to the compressor, and the compressor is pumping correctly, the only other possibility (although unlikely) that I can think about is that you were actually trying to fill the system through the high side port and not through the low side port. The low side pipes/hoses are always bigger diameter.
     
    Qavion likes this.
  11. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #36 bayferrari, Oct 1, 2019
    I think that may be it. Both fittings for high and low have been adapted to take the 134a fittings. I just assumed that they were done properly but I think adapters are reversed. I’ll check on the morning.
    Maybe I have been trying to fill thru high side all along. Low, blue fitting is very difficult to get on, pointing at clutch braided line. Red, high fitting is pointing out towards luggage compartment. Can someone verify this? I can swap fittings and place them correctly.
     
  12. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #37 m.stojanovic, Oct 1, 2019
    The diagram shows the Low side port as facing the luggage compartment, attached to the bigger diameter pipe, i.e. the top pipe connected to the expansion valve:
    Image Unavailable, Please Login
    The smaller (lower on the valve) pipe is the delivery (High) side. It comes from the receiver/dryer.
     
    Qavion likes this.
  13. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #38 bayferrari, Oct 1, 2019
    Yes, that was it. Fittings for high, low were installed wrong way. I’ve been trying to fill thru high side. It’s always something so obvious you miss it. Running vacuum now, will try a fill later this morning.
    Thanks for all the help, I would have never caught it. Life is good again!
     
    Qavion likes this.
  14. m.stojanovic

    m.stojanovic F1 Rookie
    Silver Subscribed

    Dec 22, 2011
    2,759
    Malaysia - KL
    Full Name:
    Miroljub Stojanovic
    #39 m.stojanovic, Oct 1, 2019
    Are you applying vacuum to both, Low and High ports?
     
  15. bayferrari

    bayferrari Karting
    Silver Subscribed

    Mar 10, 2011
    94
    Bay Area
    Full Name:
    William
    #40 bayferrari, Oct 1, 2019
    Yes I did vacuum both hi and low. After swapping valves system took a charge and I have cold ac!
    Couldn’t have done it without Ferrari chat.
    Got it working just in time for fall weather.
     
    Qavion likes this.
  16. Carmellini

    Carmellini Formula Junior

    Jul 16, 2019
    814
    #41 Carmellini, Oct 2, 2019
    great news and kudos for your tenacity; good form
     
Page 2 of 2

Share This Page