Cummins Aftercooler Maintenance

[Vince Luciani]

It’s been 3 years since my repower with the Cummins 330’s and I’m tackling the maintenance of the afercoolers for the first time. All in all, it wasn’t that bad a job. These pics are of the starboard engine aftercooler. Things looked pretty clean when I took it apart except for the salt buildup on the bottom cap. It’s probably good that I did them this year because if you look close on that bottom cap you can see where there was some leakage past the O-rings. The top cap was real clean and no signs of leakage.

Getting the core out wasn’t too bad. I did have to wack it pretty good with a block of wood. (you can see some evidence where I buggered up some of the tubes with the wood). I needed to hit it, not because it was frozen, but simply to move it. The fit is real tight. Nothing was corroded or frozen. I was surprised to see the inside of the air box is coated with some type of coating (epoxy?) and that coating was in great shape. I was scared from reading on the Tony Athens site about the bronze on aluminum corrosion issue, but the bronze doesn’t come in contact with the aluminum if the coating isn’t compromised. The fins of the core were pretty clean. I sprayed them with brake cleaner and there was not much to clean.

Going back together was pretty easy..I’m embarrassed to say that I installed the core in the wrong direction at first. There’s a little arrow showing the direction of the air flow. I had to take the core out again and reinstall. I greased everything with a marine grease with Teflon that I got at West marine. Tef gel might be better for the application but I couldn’t find it. Hope everything went back together right!!!

Did I miss anything guys?

Vince

Here’s some pics!


This is what I found when I took off the bottom cap.



Note the salt buildup???



More of the same



All cleaned up



Top Cap. Note how much cleaner than the bottom.



Here’s the core. Good shape!



Air box looks real good and clean. Note the black coating.



Core reinstalled, new O-ring and well-greased.



Back together.

[amuh60]

Thanks for the post. I will be doing this maintenance to my 330s soon. Pictures really help and show the process. How many hours on the engines? How many hours do you put a year? Do you store your boat out of the water any? Just curious to get an idea of how often they need cleaning! I will post the results of my maintenance.

[Ironman]

Got 330s also..
Did mine last year.. looked about the same.
I had a zinc rolling around in there.. looked like a torpedo sinker.. lol
I had around 500hrs.. good time to do it ,& loaded them up with tefgel..

Wayne..
ps, how many hours did you have?

[bob lico]

normally we use white lithium grease . sort off s.o.p. for all aftercoolers.i might add when you remove the aftercooler bottom zinc (twice a year )clean the bottom bowl you can even make big q-tip of rag and wood and clean it out as routine maintenace.

[Vince Luciani]

Guys,

I have about 400 hours on my engines. I leave the boat in the water from April 1 to December 1 every year. Normal season I get about 175 hours. Bob, good tip on cleaning out bottom bowl. That was the bad one since water sits in it all the time.

[Ironman]

A commercial guy told me to skip the top zinc .no zinc in top?
Wayne

[IRGuy]

Tony Athens of the Boatdiesel forum recommends the Cummins aftercoolers be disassembled every 2 or 3 years (regardless of hours) and the grease renewed, otherwise because of the disimilar metals corrosion might lock the shell and core together. He said it is standard procedure in his shop to do this on even new engines before they are released to his customers.

My engines have only 550 hours on them, but are 11 years old, and the previous owner never took them apart.. I have to do this job this spring, but have been warned that the core and shell might be locked together.

Also, over the years Cummins had three different gasket designs, and some of the counter sales people at local Cummins distributors have sold people the wrong gaskets, so be sure your old and new gaskets look similar.

[Bruce]

Not just cummins but all engines that have aluminum housings should do the grease bit.

Many a tube bundle could not be removed and thousands spent on new components while the old stuff found its way to the scrap yard.

If you find your tubes stuck and have to bang on them with wood to remove, make sure you pressure check before install as one cracked solder joint will introduce water injestion.

Just saw it on a 450hp C series Cummins.

[In Memory of Vicroy]

Bruce - would TefGel instead of regular lithium grease solve that problem? I've used the stuff on a lot of "impossible" applications and it seems to stick around a loooooong time.

UV

[Bruce]

UV,
I wouldn't bother with the tef gel. Lith grease is just fine as its a scheduled maint thing anyways.