Cummins QSB 6.7L Heat exchanger corrosion

[Bob Urso]

Good morning.  I have these engines in my 2015 Merdian.  At 450 hours and as part of annual service, which I do religiously, Cummins identified that the plastic end caps were warped and as a result the end caps were leaking.  This seems to be a class problem.  What is the fix?  Are there alternatives to the plastic end caps?  

At this point Cummins has taken them to the shop, cleaned out, pressure tested, and reassembled with new end caps, O rings, and gaskets.  Not necessarily an outcome I’m excited about but I’m told by Cummins that new heat exchangers are 6 to 9 months out due to current supply chain issues.

Looking forward to receiving any good insights and recommendations.

Thank you.

Topic

[Tony Athens]

The plastic caps that were designed for the QSB 6.7 HX end  were engineered by a “pure & simple” couch engineer. IMO, the idea was good, but!!  After I saw few failures, I cut one up and it was obvious what the engineer  was fixated on and he missed it big-time .. Cat made one that has worked out well.  Anyway, Cummins has  replaced it by bronze  units.

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