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Sanden Service Ports

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  • Sanden Service Ports

    I have a '99 Suburban with a Sanden U4440 compressor installed. I need to replace the high pressure service port. I can see oil from it leaking. May as well do the low side too given its age.

    What replacement ports fit this Sanden compressor? Websites and retailers want to look it up by vehicle application. A '99 Suburban came with a GM compressor not a Sanden. I looked through the Sanden service manual and there was no reference to replacing service ports.

    I could take the old part to NAPA, etc. and try to match it up but would prefer to know I have ordered the correct replacement parts.

    Thanks for any help.

  • #2
    Two choices if on the top possibly a replacement for the belly leaker on the 5.7 most common. That was a ball valve, they all leaked! Just look at it like a close up of a ball point pen.

    So if just bubbling oil (most do of that type) count on a real good OE or replacement cap and don't touch it. Check it with even soapy water that it's tight. That's the final seal plus needed anyway keep junk out would cause any to leak.

    Never replace one just the caps. I don't bother with the high side after that if at the age now anything needed maybe just periodic boosts can go by temp rather than it's pressure is exact by the chart here or I can post it.

    Yes - you can try to remove it without wrecking anything if working now but check first at a NAPA I find my best shot around me just may wait a couple days? Ask first. Then if you wish be oh-so careful removing whole valve the alloys can stick like they are welded not much works. Try Power Blaster where its threads are if you must. Expect to really destroy the thing taking of out/off.

    More: If you do also ask if a Shrader type will fit IDK I'd have to ask.

    Just a few still own one the original Delphi belly leaker is tight still?? I also unplug the LPCO at the accumulator for known off season it will cycle on even without defog/defrost request if low charge (they leak thru shaft seals when old and very cold out) with no evidence so don't let it work while too low the oil doesn't move and wrecks it!

    If you pull that trick do allow it to run periodically in off seasons till you notice cold air measured out panel vent + touch and feel right up top of the thing but must be a warm enough situation to stay engaged and need to work or at least can.

    Refrigerant when way too cold isn't going to behave IDK why almost all do that crap it wrecks compressors needlessly! That "OFF" switch will NOT 100% disable it alone!

    MetroWest, Boston


    • #3
      Circling back on this one. I finally got around to fixing the Suburban. Upon closer look, the service port is built into an aluminum block on the hose. It's not on the compressor. That said, the replacement part is unchanged by the move from a GM to a Sandon compressor. $4 at the local big box auto parts store bought me a replacement port. Used a special 8-sided socket to remove and install the fittings (easy). Used some Nylog on the seal, pulled vacuumed for an hour, held vacuum unchanged for two hours, charged with R134a and I'm fixed. Hope it helps the next guy.


      • #4
        Thanks for the follow-up: Speak for myself only + maybe. I just don't use the high side on the few remaining on those they all leaked it you touched them. Another similar I removed a used port (low area grabbed with very effective but generic plumbing type tool) just to stay sealed. I did NOT pursue the socket for it at a glance didn't think it would come off or be usable at all if so and into the whole hose set deal and Domino of alloy connection all breaking too try to avoid that for one last fix for a vehicle or give up on A/C. LOL, you can where I am but wouldn't like that last few days spiked to close to real air temp 100F just for a few hours still really nasty if you must use that vehicle.

        Good luck it stays working as long as you need it to,
        MetroWest, Boston