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Caterpiller c18 1000 hour service

Discussion in 'Engines' started by johnnwhite, Apr 24, 2026 at 8:03 AM.

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  1. johnnwhite, Apr 24, 2026 at 8:03 AM
    #1
    johnnwhite

    johnnwhite New Member

    Joined:
    Feb 6, 2019
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    Location:
    ohio
    I have a 2009 Hatteras with c18 used in fresh water for 16 years and now salt water for 6 months

    Bought the boat with 900 hours and a flawless cat survey , original aftercoolers
    now 1300 hours and why is the 1,000 hour service require after cooler replacement?

    I don’t have a warranty left on these
    No evidence of leakage
    Fresh water use
    Caterpiller doesn’t require service of the after cooler at 2,000 or 3,000 hours so why at 1,000

    cat dealer wants to replace , cable marine will inspect and test however they want to order a replacement

    is this just warranty work and extra maintenance
  2. Capt Ralph, Apr 25, 2026 at 4:25 PM
    #2
    Capt Ralph

    Capt Ralph Senior Member

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    It may not be a hour issue, or operating water; just the age.
    Any history of the charge coolers getting replaced before?

    If those are original charge coolers, I would recommend replacing them also.
    Pat on them with a smile, they have been good for 17 years.
    They usually last 5 years.
  3. K1W1, Apr 26, 2026 at 9:55 PM
    #3
    K1W1

    K1W1 Senior Member

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    The early ones did hsve a nasty habit of leaking. Get them presure tested and crack tested and make a decision based upon the results.
  4. Capt J, Apr 26, 2026 at 11:00 PM
    #4
    Capt J

    Capt J Senior Member

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    The 1000 hour service is EVERY 1000 hours. You need to clean all of the coolers. There are many......heat exchanger, aftercooler, transmission cooler, oil cooler, fuel cooler etc. Aftercoolers should be REPLACED every 6 years.
  5. DOCKMASTER, Apr 29, 2026 at 11:36 AM
    #5
    DOCKMASTER

    DOCKMASTER Senior Member

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    The aftercoolers are arguably the one weak link in an otherwise fantastic engine. Yes, I'm bias as I have C-18's too. The recommendation to replace them is not tied to your 1,000 hr service. The recommendation is due to age. As Capt J stated, 6 years is the interval. If your aftercoolers are original, you're at 17 years so way overdue. Only you can answer how much risk you are willing to take to keep extending the use of them. My C-18's are just coming up on 6 years in service this summer but I barely have 500 hrs on them. Mine spent more time out of the water than in so I may try to squeeze another year or two out of them but nothing beyond that.
  6. Capt Ralph, Apr 29, 2026 at 12:19 PM
    #6
    Capt Ralph

    Capt Ralph Senior Member

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    Has it been 6 years already?
    Time flies when your having rum..
    DOCKMASTER likes this.