Results 1 to 8 of 8
  1. #1
    Join Date
    Jun 2002
    Anybody ever had a oil pump on 40-60 hp hemi hermetic recip have a " vapor lock" and not pump oil(0 psid). This occured on a replacement compressor on start-up. Compressor had proper oil charge.

    Never heard of it before but haven't fooled with recips for awhile.

  2. #2
    Join Date
    Jun 2002
    Make that a "semi" hermetic. Got my soon to be new truck on my mind

  3. #3
    Join Date
    Jun 2004
    Richmond Virginia
    There are a few compressors that have a one directional oil pump. That is, the rotation must be correct for the oil pump to pump anything. That's the only time I've seen what you are describing.

  4. #4
    Join Date
    Apr 2004
    Rossville, GA
    Oil temperature is critical, cold oil kills positive displacement lubricated pumps pending application. Most compressor manufactors recommend that you prime the pump prior to start up or should i say it's a good procedure for such task. On the other hand i've seen many started up with no prime and run fine with good crankcase temp/press readings. I think 10 times on the discharge oil port is a good procedure with your oil pump. Vapor lock, what a sorry ass word.....And additionally don't buy a hemi when you can build stroker motor

  5. #5
    proper oil charge has nothing to do with oil pressure anyway. unless you lower than the oil screen.

  6. #6
    If this is a Copeland the oil pump is non directional. If the oil screen is not pluged and the pupmp is good it should pump. If it does not you can remove the plate on the face of the pump and remove the pump and inspect it to see if the drive is broken off of the gear. Be careful not to dislodge the pump body from the compressor body and you will not need gaskets. The pump cover is sealed with an o-ring that you should be able to reuse to reassemble. If it is broken and this is a new compressor get the wholesalehouse to give you a whole new compressor. Otherwise replace the oil pump. If the oil pump looks good but you still have 0 psi oil pressure get a new compressor. The crank is probably missing a plug where the oil passages are drilled. This HAS happened to me a couple of times.

    Good luck

  7. #7

    oil pressure

    I learned along time ago to always pump oil into the oil pump on startup of a larger( 7 1/2 and up) it's just a good practice to get into. If the pressure doesn't come up and steady out it's time to return the replacement.
    Best Regards

  8. #8
    Join Date
    Jul 2004
    If your having problems with oil pressure on start up - what were your procedures in starting? Is there refrigerant in the oil? What condition is the circuit in? Was proper clean up done? Did you gauge the oil pump on start up or after it threw the oil pressure cut out? Seems a lot more questions need to be asked before you throw out the "vapor lock" comment. However - Copeland does state this in their engineering bulletins and it is common occurance - go to the following web address:

    Register - it's free - then go to detailed product info, select publications search. Search for AE-1166-R10 and for AE-1182-R24. This will hold the answers to your "vapor lock" comment on Copeland oil pumps.

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