Another QSC Exchanger/Cooler thread

[Kyle G]

The motor is a 2007 QSC 8.3 500hp. About 1100hrs used in saltwater. No fresh water flush after use. So I finally got around to taking my cooler and exchanger apart. Pics below. I have a few questions. For the heat exchanger, the tubes seem pretty slimy on the anti freeze side. Is this normal? Will the acid bath take care of the crud in the second pic? I rodded the tubes and most of it was clean. the third pic shows what came out. In the 4th pic, could I use emery cloth to clean that up?

The after cooler is next. Curious for opinions on how it looks? Will the acid take care of the crud in the 9th pic?

Thanks

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westbrook_tate

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[Kyle G]

The stubby ratchet makes sense, Thanks!

[Rob Schepis]

Kyle,
This is one of many “by feel” assemblies but if you want actual torque specs see attached. Your aftercooler cap bolts are M10 x 1.5 into Aluminum. Especially into Aluminum I do recommend installing by feel — get a stubby ratchet or stubby wrench and make them tight, not TIGHT. Much safer to not overtighten when using a shorty. Hope this makes sense?

[Kyle G]

So I watched the youtube video on servicing the after cooler/heat exchanger. It says not to over tighten the end cap bolts. That is a pretty broad interpretation. Is there a suggested ft/lb number on a torque wrench that I should be going for?

[Bob Foster]

I had a small amount of green patina on my fins also on the bottom side of the core. I suspect it is caused from condensation “pooling” on the fins. I cleaned the best I could and pressure tested to make sure there are no leaks.

Awesome write up!

– Bob

[Tony Athens]

If the green patina on the copper fins bothers you , spray with CLR or something like that- leave it on for a few minutes.. Wash off and dry—Mist lightly with some WD-40..

Tony

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Kyle G

[Rob Schepis]

Pressure test it and the re-assembled unit.

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Kyle G

[Kyle G]

Finally got chance to start cleaning the cores. It seems like I have some corrosion on the after cooler on 1 side. Is this something that I should be worried about? Is there something I should be using to clean this up?

Sorry for all the questions but it is my first time going through this process.

[Rob Schepis]

No need to replace. Once the cap is reinstalled the rubber will be captively held in place. You can use your glue of choice to hold it in place to aid in assembly if needed.

[Kyle G]

Today, I started cleaning up my end caps on the heat exchanger and after cooler. When I was working on the after cooler, I noticed that the rubber divider was starting to become detached. Pics below. Can I use something to reattach it? Is it supposed to be attached? It seems like both ends are doing this.

[Tony Athens]

QSC Cooler Servicing

You are doing a 1st class job………………………………Put together “How Too” article to share.. I’ll do my best to make you famous and send you some T-shirts..

Sharing stuff like this is what this is all about..

You Can Do It!

Tony

..

Tony

[Kyle G]

Tony Athens wrote:

NO acid on the copper fins……………………..10:1 Pool acid mixed w/ water inside the tubes only, end plate and bronze caps.

Aftercooler core looks pretty good. Use spray cleaners or ultrasonic..

Aftercooler housing & sealing surfaces condition is ?

Coolant side of tubes on HX– Usually a alkaline based cleaner will clean that or ?? Try some newer spray cleaners..

Tony

Thanks for the replies

My plan is to use the purple simple green for the after cooler and inside the housing. Regular simple green for the outside of the heat exchanger. The Works toilet bowl cleaner at 10:1 for inside of the tubes. I picked up some 180grit plumbers cloth to clean up the mating surfaces.
I took some pics of the housings this morning.

[Tony Athens]

NO acid on the copper fins……………………..10:1 Pool acid mixed w/ water inside the tubes only, end plate and bronze caps.

Aftercooler core looks pretty good. Use spray cleaners or ultrasonic..

Aftercooler housing & sealing surfaces condition is ?

Coolant side of tubes on HX– Usually a alkaline based cleaner will clean that or ?? Try some newer spray cleaners..

Tony

[Rob Schepis]

The acid will take care of the seawater side organic crud and slime. A degreaser (or ultrasonic bath) is needed for the oil slime residue such as the air side of the aftercooler.

[Author]

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