Cummins Marine Diesel Repower Specialists › Forums › Cummins Marine Engines › 6 CTA Aftercooler housing repair while I wait for a new one…

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  • March 29, 2023 at 5:30 pm #145573

    Todd
    Participant

    Took my aftercooler in for testing at Niemic my local Cummins dealer and the core bundle had pinholes and there is pitting in the housing right up to the oring seals. Bought the boat last year, it and the engine are 1998, so time for a new one.

    Niemic tells me these are out 100 days. So I called Seaboard and the helpful parts guy told me they have the core, but similar bad news on the housing. He also told me that Seaboard is working on its own AC for the 6 CTA (hooray) but that supplies were spotty and they recently had some finish problems with the housings.

    Plan was to launch the boat in April and I cannot find a replacement AC anywhere. I was hoping someone might have a used one on a trashed engine, but no luck so far and launching in late June or July would be a disaster.

    So, plan B, suggestions have ranged from bypass the AC and run at low RPM or spray weld the surfaces of the AC openings and re-machine them to spec. 

    I only need it to work for the amount of time it takes me to get a new permanent replacement.

    I like the spray weld option, as I live near the New Bedford Commercial fishing harbor and there are a number of good welding/fab shops but I am told I need to provide the alloy of the housing. So, any ideas on the spec for the metal on a 1998 6 CTA 8.3M AC housing?

    Another idea fielded is to double the seals and slather it in 5200 and tighten it down, but that sounds a bit too jury rigged to me, unless someone has tried something similar successfully.

    Thanks for any ideas! Or, does anyone know a guy that knows a guy that has one lying around?

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  • April 8, 2023 at 3:14 am #146177

    pwrobert
    Participant

    A possible suggestion

    I have used an Italian product called Belzona 1391T for such an issue before with good results.  The trick is to blast and clean the surface and have all oils and grease gone.  Apply a thin coat with a fine wide artist’s camel hair brush.  On curved surfaces like the inside of the AC I like to use something like a piece of the wall from a 4 inch PVC pipe with stick-on PSA sand paper (various grits) to finish it down. The curved backing helps eliminate flat spots. When the core is slid in it will leave a slight mark denoteing any high spots.  Sand and Repeat as needed.  

    As far as the face iit too can be treated the same way but I prefer a new flat 12 inch long file to dress down the O-ring surface.

    Belzona makes a range of products but I have used this particular one for ten years or more as it is the High Heat version.  My first experience was using it to coat the cast iron end caps on my Generac marine diesel 8 Kw generator’s heat exchanger.  They only made them for a few years and got out of the marine area but this has been a good one for me.  Anyway by coating the cast Iron endcaps and some of the exhaust parts I extended the replacementcycle from 2-3 yrs to over 10 (also freshwater flush so that in itself added some life).  This particular use is exactly what the product was designed and marketed for – inside of heat exchangers.

     

     

    April 6, 2023 at 4:53 am #146082

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    Yes, inside not critical, just annoying.  Your machined ends where the o-rings sit don’t look too terrible, only take off what you need to, shouldn’t be much removal at all.

    As to posts by Tony, here’s one thread:

    6BTA Spool Up Issue

     

     

     

    April 6, 2023 at 4:07 am #146081

    Todd
    Participant

    Hi Mike,

    Thank you, I appreciate your experienced view on this.

    Todd

    April 5, 2023 at 9:51 pm #146069

    Mike Mason
    Participant
    Engines: Qsb 5.9 380
    Location: San Diego
    Country: Us

    Don’t worry about the inside corrosion. I have seen a ton of these aftercoolers with this. It can be from condensation sitting in the cooler. What you need to make sure is the surface where the o ring sits is in good condition. That with a new bundle that has been pressure tested and you will be good to go.  I test both the core and the entire unit once reassembled just to be sure.

     

    these housings are aluminum and will corrode with condensation over time. Usually resulting in elevated aluminum readings in oil samples. <br /><br />

    ask me how I know!!!

    April 5, 2023 at 1:56 pm #146049

    Todd
    Participant

    Thanks Rob,

    So just to read this back since I am not familiar with it and I want to ensure I get the instructions right to the machine shop:  ( I have searched and not been able to find where Tony discusses this)

    There is about 30 thousandths extra length in the AC body.

    Take in down 10-15 thousandths to get a smooth surface.

    I’ll then get new seals reassemble and pressure test. Then off to the races.

    It looks like I can get a new core locally, so I will start with that. I am calling the Seaboard parts desk to get on the list for a new seaboard style housing.  Although looking at this one, it is pitted inside from seawater leakage, but does not seem to have a performance or structural impact? Maybe it has life left after machining the sealing surfaces? I added some pix here. Not experienced with this issue so maybe a bad idea to try to keep it for a while?

     

    March 30, 2023 at 12:02 pm #145639

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    The number Tony references is 30 thou (the typical credit card thickness although they are making them thicker these days) but I agree, block sanding could do the trick there.  Can also dress it with some good cleaning, prep and a thin smear of epoxy sanded smooth.  But the core?  What’s you’re temporary plan there?

    March 30, 2023 at 8:37 am #145615

    Gene Fuller
    Participant
    Vessel Name: Yorkshire Rose
    Engines: QSB5.9 380
    Location: Punta Gorda, Florida
    Country: USA

    If I recall correctly there is something like an extra 40 thousandths or more of clearance for the length of the core.

    Just take the housing ends down by 10 or 15 thousandths by milling or even careful filing. The surface should look a lot better.

    I believe this has been recommended by Tony numerous times.

    March 30, 2023 at 7:33 am #145609

    Todd
    Participant

    Rob- see two photos here

    March 30, 2023 at 7:30 am #145608

    Todd
    Participant

    Yes, Dougin, in MA, and thanks will check into a bigger oring

    March 30, 2023 at 5:49 am #145597

    Douglas Fairchild
    Participant

    Used housing

    Hi Todd     You mentioned New Bedford are you  in Mass.  I am in Ct and replaced my 02 after cooler housing and core last year.  It was leaking but not too bad.  I have pitting in my housing but not up to the very top.  The gap between core and housing is slightly larger.  A larger o ring may be good enough to carry you through a few months.    Doug

    March 30, 2023 at 4:29 am #145595

    Todd
    Participant

    Hi Rob, I am trying to get some photos today.

    They did a soap test on the bundle produced a huge amount of bubbles from the middle area so did not seem fixable.

    March 30, 2023 at 4:24 am #145594

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    How about some pics of the housing issues?

    And the core, is that repairable?  Bypass the bad tubes (plug them)?

    March 30, 2023 at 2:52 am #145586

    bluebyu
    Participant
    Location: East Coast
    Country: USA

    Another option could be to have a good machine shop bore it out and sleeve it.

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