QSB6.7

[Roy Beasley]

I have a small water leak coming from the rear of the aftercooler on QSB6.7.  I am assuming it needs a new o-ring.  Is there 2 o-rings on each end? Just take off rear cap and replace them.  Is this as easy of a fix as it seems?  When time allows, I want to have the aftercooler pulled for maintenance but just wanted to get the leak stopped for now.

 

Roy

Topic

[Roy Beasley]

Pictures attached.  You can see the light brown area where it is leaking.

[Tony Athens]

Without good pictures of the SPECIFIC leak, not sure how any comment could address your particular issue. First of all,  there is more that one type of aftercooler for a 6.7 and more than one type of connection. Farther away and close up is needed if you want  solid answer to YOUR leak.

[Roy Beasley]

Thanks pwRobert. Very helpful. That was kind of my suspicion that it wouldn’t necessarily be that easy.

[pwrobert]

It’s Seldom Small with Aftercoolers

Leaks around the caps of aftercoolers are almost never a simple matter of changing out the o-rings.  Even if the O-ring is the only failure you would have had to catch it pretty quickly as the edges of the aluminum housing are notorious for quickly pitting and requiring resurfacing due to bronze and aluminum mating each other.  Even if you are lucky and it is just an o-ring the entire disassembly is waranted anyway.  

There is just one o-ring for each end.  Size depends on what the units has previously  installed.  That is why Seaboard just sends both sizes in all packages.

I “just had a leak” a few months ago and never got any signs or symptoms while running.  Just noticed the lower end cap sitting with a gap larger on one side than the other.  It may have been one throttle down from a blow out. Disassembly showed a bolt that had stripped out of one of the threads in the aluminum housing and moderately pitted the housing.  And yes I do a pretty good job of fresh water flushing my engines reguarly.  I ended up planeing down the pitted surface and putting in two Heli coils. Another bolt was about to give way and could just tell it was not feeling quite right when tightening down on reassembly.  Went ahead ad took off the other aftercooler and did it’s entire service as well for good measure.  They had both  been service just 12 months previously.  I think the threads in the used aftercooler were weak from the time purchased but who knows three years later.

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