Cummins QSC Exhaust heat exchanger service

Discussion in 'Diesel Engines/Drives/Transmissions/Props' started by Carpediem44DB, Dec 21, 2019.

  1. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    So I am waist deep in the winter service which is including all seawater side servicing. I am using the data from Cummins Quickserve but I can't find any info on the Exhaust heat exchanger R&R and service. The only thing in their manual for the cooling system is for 500 hr or 1 year inspection of hoses and coolant top off. Am I just missing something? I removed the after cooler and oil and fuel cooler today and was going to dig into the exhaust side in the morning. Its all pretty straight forward but I like to have the instructions to go by to avoid doing something expensive! Anyone have any tips or instructions from a manual that isn't on Quickserve?
    Thanks
    CarpeDiem
     
  2. ZZ13

    ZZ13 Well-Known Member

    Nov 25, 2009
    Lady's Island, SC
    2001 400 Sedan Bridge
    Cummins 450 Diamond
    Not sure if this helps but this is from the B&C Series Marine operation and maintenance manual. I change my coolant every 5 years, though.
     

    Attached Files:

  3. flyboycj84

    flyboycj84 Member

    86
    Feb 20, 2014
    Merritt Island FL
    2008 Meridian 391
    QSB 5.9
    Lots of good HX info on sbmar.com, both forum info and articles. I’m not really familiar w the QSC HX and if it’s different from my QSB......but I’d assume it’s similar. Rod out what you can if your tubes appear blocked, cap one end, stand upright and fill with a 10:1 ratio of pool acid and water (or Barnacle Buster, Descale, Rydlime, whatever) and let boil for 30-60min. Then flush thoroughly w water.
     
  4. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    Thanks that’s sort of the plan. I pulled mine today and they definitely need service. I found the remains of at least three finger zincs and the resultant debris blocking about 50 percent of the core. I never see above 170 F. The core popped right out so lm gonna soak in Muriatic and rod out.
    Cheers
     
  5. flyboycj84

    flyboycj84 Member

    86
    Feb 20, 2014
    Merritt Island FL
    2008 Meridian 391
    QSB 5.9
    Are we talking heat exchanger or aftercooler? Does the QSC heat exchanger have a core?
     
  6. flyboycj84

    flyboycj84 Member

    86
    Feb 20, 2014
    Merritt Island FL
    2008 Meridian 391
    QSB 5.9
    This is a great article on the aftercooler portion of your service.......I pretty much followed this procedure.....Tony says NOT to soak the air side of the core in the acid.....rather spray clean with brake cleaner or simple green or whatever. I also pressure tested both my core, and housing, after the service.....using test rigs I built.

    https://www.sbmar.com/articles/cummins-marine-aftercooler-maintenance/

    591EEA08-0C71-408A-AF74-4311C0250B1D.jpeg D40143F3-472B-476E-A37D-09D3B8C2E970.jpeg B0DC6623-0D6E-4174-B68C-E1EF706E0B92.jpeg DBE7C40C-ED75-43AF-AC74-D8BD9227B2BB.jpeg B9BBEAEA-FC85-4E3E-91D4-E61E7565F2FE.jpeg
     
    Last edited: Dec 22, 2019
  7. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    Both have cores. I inadvertently put exhaust in the tread title. I am servicing everything on the seawater side of the cooling systems this year. Its the first time they have been apart as far as I can tell. When I bought the boat it only had 118 hrs on it as it was used as an occasional condo. I never saw any indications of corrosion so I put off opening up the system until now. I think except for a minor amount of pitting in the aftercooler housing every thing should clean up well. Ill now do it religiously every three years. I really was dreading the job but it has gone way easier than I had feared it would.
    Cheers
     
  8. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    Thanks, I was a little apprehensive of soaking the whole AC core actually. I'm soaking up as much info and advice as I can before I proceed for sure.
     
  9. flyboycj84

    flyboycj84 Member

    86
    Feb 20, 2014
    Merritt Island FL
    2008 Meridian 391
    QSB 5.9
    I did the same. Tried to read up bigtime before I did it. The hardest part of the job was just getting the port aftercooler in and out, and the stbd heat exchanger. There’s not a ton of room on my boat outboard the engines. I would also HiGHLY advise installing a freshwater flush setup. I haven’t added it yet, but plan on doing so. And if it means only having to do this job every 4 years......than sign me up, lol!!!! Sbmar says you can really stretch out the bench service by freshwater flushing.
     
  10. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    IMG_0873.jpg IMG_0878.jpg IMG_0882.jpg IMG_0883.jpg
    Access is definitely a bear. I'm glad I'm not built like a line backer for sure. I installed a nifty salt neutralizer injection system that seems to work pretty well but flushing with fresh water also would give me even more peace of mind. I'll know for sure when I do this again in three years.
    Other than a small area of corrosion and a screwed up silicone seal they look pretty good for a boat that has only seen saltwater its whole life.
     
  11. flyboycj84

    flyboycj84 Member

    86
    Feb 20, 2014
    Merritt Island FL
    2008 Meridian 391
    QSB 5.9
    They don't look terrible. The most important area to look at is the mating surface where the O-ring is. Mine was pitted slightly....i took a couple mils off with a sanding block and that was sufficient. I also sanded the copper ring on the core that the o-ring seals against. I'd rod those tubes out, and then stand upright and fill with 10:1 acid/water and let boil for awhile....they'll clean up nicely I think. I wouldn't use straight acid. I did this by putting some plastic around one end of the core, and using a big hose clamp around it....this lets you fill the inside with the acid, and it won't flow out the bottom. It worked pretty good. Lube the heck out of the inside of the housing, and the oring mating surfaces on rebuild. Alco Metalube is what I used, and recommended by sbmar. I got it on Amazon.

    As for the air side...no acid....I used brake cleaner on one, and I tried to simple green on the other. Both worked well.

    As for the caps...they clean up super nicely if you just dunk them in the 10:1 bath for an hour or so. The zinc will completely dissolve, as well as the remnants of the old. \

    Fuel cooler, and gear cooler both got the same 10:1 acid bath that the core got. I capped off the trans fluid ports, and the fuel ports before i dunked them. Flush everything thoroughly after.

    I'm sure you've seen most of this, I'm just adding some things that maybe weren't written elsewhere, and may give you a better idea of what's what.
     
  12. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    I'm working on that this morning. I ordered new silicon seals for the after cooler from SB this morning. Thankfully the sealing surfaces are perfect I just have pitting where the copper met the aluminum in the bore. Hopefully ill have the starboard engine back together by the end of the week and can do the port engine. I'm off for winter break until the 13th so Ive got plenty of time to get a bunch of projects done before our first club cruise out at the end of Jan.
    Thanks for sharing your tips.
    Rusty
     
  13. BlueYonder

    BlueYonder Member

    148
    Jan 12, 2015
    Chesapeake Bay
    37
    QSC 8.3 600
    This is from Quickserve for the QSC 8.3. Flush the after cooler every year or 500 hours whichever comes first. The maintenance at 3 years is the major aftercooler service. If you click on the note at 7. It will take you to the instructions for removing and disassembling the aftercooler.

    Screen Shot 2019-12-22 at 14.22.23.png
     
  14. Carpediem44DB

    Carpediem44DB Well-Known Member PLATINUM Sponsor

    664
    Aug 18, 2015
    Sanfransico Bay area
    2006 44 DB Sedan Bridge Raymarine gs165 w Quantum HD Radar
    Achilles 350 Dink
    Nick Jackson Davit
    Cummins QSC 8.3 500 HD
    Well I'm finally about done with my winter service projects. I ended up removing and servicing the heat exchangers, aftercoolers and fuel and oil coolers. I replaced the impeller and intake hose on the port engine as well as drive oil cooler hoses. I was having a hell of a time finding the scalloped hose for the engine water intake hose so ended up using reinforced marine hose that won't make as tight a bend as the scalloped hose. I welded up a 180 elbow of 316 stainless to make the install possible. I'm pretty happy with the out come. There is one thing that will definitely let you know you are not a 30 year old any more and that is servicing the seawater components of a couple of Cummins QSCs! I hope to move up before I need to do this again. If any of you guys have 10 year old plus boats in salt water that have yet to go thru your cooling systems because you have not seen temperature issues, You would do well to get it done. I am impressed how well the components have resisted serious corrosion as mine 14 years old and never been opened but they did show signs of being over due for sure. Attached are pics of the port water intake mod.
    IMG_0978.jpg IMG_0980.jpg IMG_0981.jpg IMG_0976.jpg
     
    Mjresq4 and villain style like this.

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