Cummins Marine Diesel Repower Specialists › Forums › Cummins Marine Engines › QSB 6.7 After cooler Flush
- This topic has 19 replies, 9 voices, and was last updated 3 years ago by gerryc.
-
CreatorTopic
-
September 20, 2019 at 12:47 pm #78266
My engine has about 350 hours and 2 1/2 seasons of use. I want to do the Barnacle Buster flush before I haul out for the season here in the Northeast(NH Seacoast). Many good points on this forum. I will be using the groco replacement cover for the in flow. I plan to remove the exhaust hose at the heat exchanger. My question is will that hose remove easily without damage and go back easily?
-
CreatorTopic
-
AuthorReplies
-
February 1, 2021 at 4:40 pm #109821
gerrycParticipantVessel Name: Midnight Zulu
Engines: Cummins QSB 6.7
Location: Vancouver
Country: Canada
Update
Core only slides out aft. Aluminum retainer ring slides off forward end. Cummins part number for end caps has
been superseded for a new design. Using these bronze caps seems to be the best option. Five years old and 600 hours, It really needed this service…..lots of corrosion starting. I will hack saw the old cap to retrieve the
bolt.January 30, 2021 at 4:49 pm #109720
gerrycParticipantVessel Name: Midnight Zulu
Engines: Cummins QSB 6.7
Location: Vancouver
Country: Canada
I have the aftercooler on the bench now, and looking at Brendan’s photo, I am wondering if the core only slides out to the aft? Also. do the thin plastic strips need to be reinstalled during assembly? I gather that the barriers
are there to direct the sea water S-N-S through the core prior to exiting. I have purchased the Bronze end caps
but one of the bolts remains in the composite aft end cap because it is blocked by the zinc anode bolt which I cannot remove due to the whole sleeve turning (what a Crappy design……) Could I use a regular SS replacement bolt?November 25, 2020 at 1:05 pm #107123
Byron BiggsParticipantbarnacle Buster for HX scale removal
I see the place for BB (or equivalent) sole job is to remove scale (mineral deposits) that build up on the passage ways of the raw water HX (any type). It does not take much (as in a couple of .001’s) to decrease the thermal transfer. Think of mineral deposits as “Pink Panther” for your HX. Saying all that I do not know the degree that which BB attacks the copper or brass HX passageways. I suspect very little. Also BB is no substitute for cleaning the air side of the core on your after coolers.
October 16, 2020 at 2:58 pm #105336
gerrycParticipantVessel Name: Midnight Zulu
Engines: Cummins QSB 6.7
Location: Vancouver
Country: Canada
QSB 6.7 in Nordic Tug
Glad I read these posts as I am in the process of servicing my raw water system. I realize that I also have plastic end caps, not to mention the whole insert sleeve turning while trying to remove the anode on the rear cap.I am now in touch with my guy in Victoria BC regarding the Bronze replacements (as well as an SMX pump
to change to at the first sign of a drip) I have purchased a Groco 2″ inline fresh water flush system and my question is; am I OK to install it on the output side of the strainer, or should it be installed between the through
hull valve and the strainer unit. That hose is much shorter and could make for a more difficult job when trying to fit. Thanks again Guys,October 23, 2019 at 7:18 pm #79781Yes, you can use Barnacle Buster. It does help clear the cooling passages from marine growth. I have used it twice now and seen temps lowered on intake manifold and head cooling. Good for a/c and gen set. But, like mentioned above, it does not address corrosion around the sealing o-rings. I use it once a year and disassemble and rebuild every 4 years in SoCal. 85-100 hrs a year.
October 19, 2019 at 3:25 am #79515Thanks for clarifying. My original inquiry was about doing a flush with Barnacle Buster as I am on a mooring without any way to have a fresh water flush set up.
I am now convinced that I need to service the after cooler. Is this done by just removing the end caps or does the after cooler need to be removed from the engine.?
In Tony’s last reply it shows the heat exchanger what is the suggested maintenance for it?October 12, 2019 at 6:46 pm #79246
Tony AthensModeratorVessel Name: Local Banks
Engines: QSB 6.7 550 HP
Location: Oxnard, CA
Country: USA
100% right………………..Had them swapped in the 72 year old brain..
Tony
October 12, 2019 at 11:35 am #79224
AnonymousInactive6.7 aftercooler serviceability
i believe you are thinking of the 6.7 hx. Which does not come apart other than the end caps come off.
October 12, 2019 at 8:49 am #79220
Tony AthensModeratorVessel Name: Local Banks
Engines: QSB 6.7 550 HP
Location: Oxnard, CA
Country: USA
6.7 aftercooler serviceability
Obviously, I have lost it….
Time for Homosassa..
Tony
October 11, 2019 at 3:52 pm #79207
AnonymousInactiveAftercooler service
6.7 aftercooler is 100% serviceable if taken care of from day 1. It uses the same o-rings as the cummins QSC 8.3. I have done about 10 of them to date.
Brass caps are a must sooner rather than later.
1 user thanked author for this post.
October 8, 2019 at 4:40 pm #79047Serviced mine with 4 season and 300 hours. 2013 QSB 6.7. Fresh water moored so basically fresh water flushed. Pull the hoses to you aftercoolers, trans cooler and heat exchangers and look to see condition. For your aftercoolers, earlier ones had plastic end caps. No good. Must switch those out. Service them and install a fresh water flush.
September 27, 2019 at 3:14 pm #78552
Tony AthensModeratorVessel Name: Local Banks
Engines: QSB 6.7 550 HP
Location: Oxnard, CA
Country: USA
Not at all……………………………The plan for my 60K -$100 + K engine room would be diligent fresh water flushing.. Acid washing would be absolutely last on my list.
Tony
September 27, 2019 at 4:11 am #78520So is the solution to not remove and service the after cooler as suggested and go ahead with the planned Barnacle Buster flush?
September 25, 2019 at 7:54 pm #78473
Tony AthensModeratorVessel Name: Local Banks
Engines: QSB 6.7 550 HP
Location: Oxnard, CA
Country: USA
It’s does appear than when these aftercoolers were on the “Drawing Board”, proper disassembly and servicing of both the core and the housing was part of the plan…………………………. So what happened? I have no clue other than what I am not allowed to refer to any more ( I’ve been slapped) ..
You said it for me.. Thanks..
Tony
September 24, 2019 at 7:02 pm #78425
PhilipParticipantVessel Name: 2007 35’ Cabo ‘FUGA’
Engines: Cummins QSC8.3-540’s
Location: Long Beach, CA
Sounds like some of the older QSB6.7 aftercoolers May have had a different design that allowed disassembly. At some point that changed and now we have a cooler that can’t be cleaned/serviced… what were the couch engineers thinking?
September 24, 2019 at 3:39 pm #78414
Corey SchmidtForum ModeratorVessel Name: Rebel Belle
Engines: Cummins
Location: Oxnard, CA
Country: USA
Well unfortunately the core is not removable for the QSB 6.7 aftercooler based on my research… not a good design IMO but it is what it is. More R&D to be done on these coolers so we can come up with a solid maintenance plan in the long-term… nothing worse than a $3k “throw-away” non-serviceable component…
September 21, 2019 at 8:56 am #78302
PhilipParticipantVessel Name: 2007 35’ Cabo ‘FUGA’
Engines: Cummins QSC8.3-540’s
Location: Long Beach, CA
No. The aftercooler has to come off to get the core out.
Save the money and skip the acid flush.
September 21, 2019 at 3:10 am #78296Thanks for the reply. I was planning to have the after cooler serviced next season. Can that be done on the QSB 6.7 without removing from the engine?
September 20, 2019 at 6:03 pm #78286
PhilipParticipantVessel Name: 2007 35’ Cabo ‘FUGA’
Engines: Cummins QSC8.3-540’s
Location: Long Beach, CA
The hose should remove just fine.
BUT
You need to understand that flushing with any acid wash will clean the bundle tubes only and will not address the o ring sealing surfaces that can cause you some serious issues. At 350 hours and 2 1/2 seasons in salt water with no fresh water flush you are due to disassemble the aftercooler and clean/grease/replace o rings in the process detailed on this cite. Failure to do this can and will eventually lead to salt water spraying into your engine.
Acid flushing is fine for a mid season tune up if needed but not a replacement for proper off engine servicing.
Phil
2 users thanked author for this post.
-
AuthorReplies
You must be logged in to reply to this topic.