Aftercooler scheduled cleaning

New boat to me - CAT 3208 435HP, 2 of them. CAT recommends aftercooler cleaning & pressure test every two years. On the calendar it will be 2 years this May but technically the boat has been used only about 1 year since it gets put away for the winter. My thinking is I could go a bit longer because of the winter lay-up. I also should mention these are rebuilt engines with approx. 325 hours since that rebuild and at that time I was told they installed new aftercoolers also.
Your thoughts appreciated?

Well if the aftercoolers stay full of sea water when hauled out, that time counts as well. Although I wouldn't try to put that fine a point on it. Two things you can do to help: drain the aftercoolers after haul out or better still flush with fresh water and drain.

Make sure that you do a complete disassembly, cleaning of both air and water sides, reassembly with new gaskets and lots of grease followed by pressure testing.

Tony Athens discusses this for Cummins and Yanmar engines in Tony's Tips on Sbmar.com. Equally applicable to Cats.

David

Aftercoolers are really expensive to replace so why not check them?

Good points David M thanks. And good question Comodave. Truth is I would like to tackle this task myself but I just bought the boat and I am in Illinois and the boat is in Connecticut. I was hoping to launch in May and get familiar with it in a couple of weeks and then head home - Lake Michigan. It doesn't look like an easy job either. The aftercooler on the port side will be tough. It will likely be a couple of grand if I hire someone to to this? So I am trying to determine if I really hit the 2 year mark or not. So that's why I ask. Always good info from you guys on the forum. Thanks.

Well, as they say, do you feel lucky? If so roll the dice and run it home. If not then have them serviced. Without knowing the service history of the engines it is difficult to say what to do.

I live in Connecticut and used to keep my boat in the Connecticut River at Essex. That water is semi fresh and if you were hauled out there your engine may have gotten an automatic fresh water flush.

So where was the boat hauled?

David

Bingo! The boat was hauled out at Essex, at the Essex Boat Works. Stored under roof for now. Essex seems like a great place to have a boat. We will spend at least a couple of weeks there before heading home. Looking forward to it.

Pat T said:

Bingo! The boat was hauled out at Essex, at the Essex Boat Works. Stored under roof for now. Essex seems like a great place to have a boat. We will spend at least a couple of weeks there before heading home. Looking forward to it.

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Essex is mostly fresh, but sometimes salty if there was no rain for a while. That isn't definitive but I think you will be fine waiting for a while to service your after coolers.

David

I agree you should be fine, but plan on doing it next winter. Keeping up with them is as much about heading off failures as it is being able to get them apart. The longer they sit, the harder they are to get apart.

Also, a failure may not just mean a new cooler, but a new engine. Because it’s on the intake side of you engine, a leak can result in ingesting salt water into the engine which does not go over well with the engine. And even in your ultimate lake destination, it’s not a good thing.

I sure do understand the possible catastrophic results of a failed aftercooler. It was what bit the last PO. As a result I have rebuilt engines and new aftercoolers but I certainly don't want to go through that. I am going find out exactly how the aftercoolers were put away/winterized and make some inquires as to the cost of having them checked out before I leave. At a minimum though I will have this done by next winter at the latest.
Much appreciated guys.

Yep...I wouldn't sweat it if you let it go another season. I personally think 2 years is overkill...especially in brackish or fresh water. I do like that aftercoolers on the later model Cummins series. They have a pinhole in the cooler. If it were leaking water that would be a fine mist coming out of that hole. Otehrwise just warm/hot air.

Do you know when calendar wise the AC's were installed?

I have worked on some 435's that I knew the AC's were never serviced in over 20yrs of hard saltwater use. The AC's were still in decent shape, but the engines were beat.

I too think the 2yr schedule is a bit nutty. On my personal Cummins 450, I do mine about every five years and it is in good shape, could probably go longer.

NE use is much easier on diesels than SE or FLA. Cooler water, shorter seasons, fresh water in the rivers.

I'd do it when you get to your home port in the GL in the off season. That thing will be dang well flushed out at that point!! Probably won't need to do it again running in the GL.

Once in the GL, the aging clock dang near stops. Always amazed to go up there and check out some engines. Engine rooms are like museum pieces!!

Salt and heat are evil.

Yes Ski, the rebuild was completed in May of 2019 in Florida. The boat then returned to Connecticut, and was put away for the the next 2 winters. I contacted the rebuilders and they told me the boat had new aftercoolers installed at the time of the rebuild. Makes sense that at least one of them was new b/c one failed and ruined an engine. PO decided to rebuild both engines rather than have one new and one old (2500 hrs.).

Pat,
Often new aftercoolers are assembled at the factory with little to no grease. It is the grease that provides protection against corrosion. If it were my boat, with twins, I would not "put off" too long a complete service of the aftercoolers. Not only are you relying on the seals to keep water (often seawater) out of your engine, but depending on your engine (blow by, etc.) and your CCV system, an oily "gunk" can clog up the air side of the aftercooler and limit the air supply (maybe resulting in overloading). Corrosion (which is accelerated if there was no grease used when assembling) is often a big problem resulting in ultimately engine failure (you know about this one), or the need to replace the expensive aftercooler because you cannot get them apart or when you do, they are so badly corroded that they are not serviceable.

As has been stated by others, freshwater flushing including operating in freshwater, can slow down the build up of (calcium) deposits and the corrosion. Check out Tony Athens' site sbmar.com and you will find lots of info on this. He advises servicing aftercoolers every 2-3 years (saltwater use no flushing) and every 3-5 years if regularly freshwater flushed. Being prudent, especially until you learn how your exact situation affects your aftercoolers, is never a bad idea (especially in this case because you don't know for sure if the coolers were disassembled and properly greased before being installed on your engines).

I haven't had CATS, but did own Cummins and the same principles apply. If you need to hire out the work the first time, insist on "learning" how to do it yourself for the future.

That is my 2 cents worth, good luck.

If you are 100% confident the OP had the maintenance done I'd drive the boat home and do it there.

it's not like they are way overdue, actually they are not even due for service yet.

Thanks Tom and Kevin for recent posts. I am leaning toward moving the boat home before I tackle this event. My reason is although the two year mark will be this May the boat was really only used about 1 year. I have the invoice for when the engines were rebuilt (finished May 2019) and that included new aftercoolers. I had the engines surveyed by CAT and the tech was not concerned or he did not mention the need to get in right away at least. I also spoke to the yard where I had the boat was winterized and I was informed that they ran the antifreeze through the aftercoolers so no salt water sitting there over this winter either.

CAT intercoolers had a bad reputation because of dissimilar metal issues in one area. That has been fixed but it suits everyone to keep changing them out (except owners). As one experienced diesel mechanic told me “he has a attic full of perfectly serviceable CAT aftercoolers”. If they have been checked and serviced regularly then trust them. If not change them out.

Ski in NC wrote: "Once in the GL, the aging clock dang near stops. Always amazed to go up there and check out some engines. Engine rooms are like museum pieces!!

Salt and heat are evil."

Another compelling reason to shop for a boat that has been living in fresh water, especially up in the Great Lakes.

Ski in NC said:

Once in the GL, the aging clock dang near stops. Always amazed to go up there and check out some engines. Engine rooms are like museum pieces!!

Salt and heat are evil.

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Ski...
I certainly agree and just scratch my head when many will argue that a fresh water boat has no premium value over a salt water boat. Not my thinking!
Not many folks around us ever talk about maintenance or replacement of headers, coolers, etc.

Aftercoolers

Pat -

Also have a GB 47 in the Newport RI area. Most likely the engines were laid up with a non corrosive antifreeze during the winter. The previous owner or his mechanic ought to be able to tell you that info. That should add to the life. I bought our boat in Feb 2020 out of FL and at the time she had about 1200 hours on two CAT C9s. As part of the closing I was credited with a aftercooler replacement agreed to price. I am pretty sure that CAT no longer recommend testing the aftercoolers but stated clearly to replace them at the 5 year point in their life. Not sure how they are tested but if you pressurize them you may just be enough to cause a leak so be careful with specs. Our boat was always in the FL region and spent most of her time in the salt water. Essentially 12 years of salt water in system with no anti freeze flush.

So just recently we pulled the aftercoolers and there was definitely rust inside the cooler casting. Looks like a little water pooling under the Port engine cooler but the good news is that the area beyond the heater and down where the valves are showed little if any rust. (see port casting attached photo) So I think we escaped without a major problem. We will put in new coolers and make sure all of the rust is cleaned up. It could be that the moist salt air coming in from turbo chargers created the rust - I don't know. But after buying the boat the engines always ran great with no difficulties.

I recommend you talk with owner about her winter layup and if the blue anti corrosive antifreeze was used, I think you are good to at least the 5 year point if that is what CAT recommends for your engines.

Bob

Thanks, and good point on the pressure test. I read where some guys take the aftercooler to a auto radiator shop? Well if so I sure would want to tell them how much pressure to use.