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Raw water pump needs replace??

Discussion in 'Technical Discussion' started by Bob48, Jun 19, 2012.

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  1. Bob48, Jun 19, 2012
    #1
    Bob48

    Bob48 New Member

    Joined:
    Jun 16, 2012
    Messages:
    1
    Location:
    Sturt, FL
    What are the tell tale signs that a Cummins raw water pump, on the 6CTA, is appraoching replacement time? I noticed green/blue staining on the right side when I recently repalced the impeller.
  2. Capt J, Jun 19, 2012
    #2
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,530
    Location:
    Fort Lauderdale
    You could try moving the impellor shaft when the impellor is removed and see if there is any play. If there is a decent amount of play on the impellor shaft it needs to be replaced. If the shaft seal starts leaking saltwater as well, it needs to be rebuilt or replaced. I've always replaced them, rather than rebuilt them.
  3. Bamboo, Jun 19, 2012
    #3
    Bamboo

    Bamboo Senior Member

    Joined:
    Dec 19, 2008
    Messages:
    934
    Location:
    Palm Beach, FL
    One of my ME Jabsco raw water pumps starting leaking from the shaft- I thought it was from a output gasket at first. Perhaps two red solo cups a minute at 1800 rpm; one at 1700 and only dripping at 1200 none below that. Replace the pump: $1600. Rebuild kit which is everything except the housing: $900. Water seal: $70.
    I replaced the water seal (+ new impeller; it was 3 years old) and it stopped leaking and continued to operate as designed.
  4. Capt Ralph, Jun 19, 2012
    #4
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    13,439
    Location:
    Satsuma, FL
    not all a seal problem

    Capt J brings up a good first test, after pulling the impeller, (without belt tension) try to move that pump shaft around. If it moves, the bearings are giving play or way, The seal will fail again.
    Over tension of the drive belt or bad pulleys will cause the bearings to give a little, then the seal looses good surface, wets the bearings and the pump turns to toast (SH****) quickly.
    Lesson; do not over tension the pump drive belt!!!!

    On my generator, after trying to rebuild the pump a couple of times, it was cheaper, quicker, smarter to have a whole new pump spared and swapped when needed. I do keep enough spares to build two more pumps but major kits do not include the shaft, the main surface seal failure area. Compare these prices to your model of pump. It may surprise you how cheap a new pump is VS working /fixing your original.
    I know it's close $ including a new shaft for my Detroit / jabsco pumps also.

    Down time sux, be a good boy scout, have a whole pump on the ready.