3116 Heat Exchanger & Aftercooler removal

cwiert

Active Member
May 7, 2008
560
Chester, CT
Boat Info
1998 400 Sedan Bridge
Engines
CAT 3116 - 350HP
Now that my boat is laid up for the off-season, I want to get to some maintenance items. At the top of the list is cleaning the HE and after-coolers. It's time to replace the coolant anyway, so this seems like a good time to do it. I plan to bring the HE and aftercoolers to a radiator shop so they can pressure test and clean. I've never taken either off before, so I don't know exactly what I'm getting myself into.

Do I need any special tools, or is there anything that I should be aware of? I'm hoping that it's self-explanatory and just nuts, bolts and hoses that need to be removed. Is there anything else I should be cleaning at the same time like the transmission oil cooler?

Any and all advice is appreciated before I dive into this project.

Thanks.
 
Our marina has a descaling system for the seawater side of the heat exchangers, transmission oil cooler, etc. It is far easier to clean the system on the boat than it is to tear it down and do it piece by piece. A side benefit is that the descaler also eats zincs so any that have been lost in the heat exchanger previously are dissolved. If you are using Cat ELC coolant, there is no need or reason to clean the coolant side of the HE. This is a much easier process than removing the tube bundle and rodding the HE out in a radiator shop and there is virtualy no risk of damaging the tubes. If you decide to remove the HE for cleaning, you will need to order a set of O-rings from Caterpillar before starting......about $50/side.

The aftercooler is a different animal. You will need to drain the coolant so it is a good time to replace it....a bit more than 30 qts per engine. The aftercooler is heavy and awkward to handle so plan on getting help with removal and re-installation. The gasket is long and flimsey so it damages easily. I would replace all the hoses and hose clamps on the aftercooler....some are formed and the Cat hose clamps are far better than West Marine or parts house clamps so you will need to go to your Cat dealer for the hoses, clamps and coolant.........I just got back from our Cat dealer this morning nd discovered t hat Car has changed the part number on ELC so ask for the coolant by name...Extended Life Coolant and the new part number is:238-8648
 
I just did both of my aftercoolers, and it was pretty straight forward. As Frank says, now is the time to replace coolant, coolant hoses and the turbo hose. For me, there was no good way to capture the coolant as it drained, so I just let it drain down into the bilge and then sucked it out periodically with a handheld drill pump before the bilge pumps kicked on. Pain in the butt and messy, but got the job done.

They are pretty heavy and awkward for sure, I managed to do them by myself, I'm not sure if having a second set of hands would have made much difference but my engine room is pretty accessible. The gasket is flimsy, be careful not to tear it. It also goes on only one way, if you have it backwards the holes won't line up. Check it before you attempt to install it and know which way it goes in. I have the CAT part numbers of everything I replaced when I did mine, I can send them your way if you would like.

Kevin
 
Our marina has a descaling system for the seawater side of the heat exchangers, transmission oil cooler, etc. It is far easier to clean the system on the boat than it is to tear it down and do it piece by piece. A side benefit is that the descaler also eats zincs so any that have been lost in the heat exchanger previously are dissolved. If you are using Cat ELC coolant, there is no need or reason to clean the coolant side of the HE. This is a much easier process than removing the tube bundle and rodding the HE out in a radiator shop and there is virtualy no risk of damaging the tubes. If you decide to remove the HE for cleaning, you will need to order a set of O-rings from Caterpillar before starting......about $50/side.

Thanks Frank. Do you have any experience with the results of a professional descaling system flush (like you mentioned) vs. something like Barnacle Buster or RydLyme? I agree, It makes more sense to clean the HE thoroughly intact vs. removing it and risking damage during removal, transport, and then installation again.

I just did both of my aftercoolers, and it was pretty straight forward. As Frank says, now is the time to replace coolant, coolant hoses and the turbo hose. For me, there was no good way to capture the coolant as it drained, so I just let it drain down into the bilge and then sucked it out periodically with a handheld drill pump before the bilge pumps kicked on. Pain in the butt and messy, but got the job done.

They are pretty heavy and awkward for sure, I managed to do them by myself, I'm not sure if having a second set of hands would have made much difference but my engine room is pretty accessible. The gasket is flimsy, be careful not to tear it. It also goes on only one way, if you have it backwards the holes won't line up. Check it before you attempt to install it and know which way it goes in. I have the CAT part numbers of everything I replaced when I did mine, I can send them your way if you would like.

Kevin

Thanks Kevin. Yeah, if you could send me the part #s, that would be great. You can PM me, or list them here. I'll definitely replace all the stuff you and Frank mentioned. There's actually a lot of other hose clamps that I want to replace, so this is a good time to do that as well.

Question for you or Frank (or anyone else): Should the T-stats be replaced regularly? Wondering if I should replace those too, while I'm in there.
 
Yes on the thermostats. Cat has a recommended interval, but I forget what it is. Replace the coolant recovery tank cap (radiator cap) at the same time. Use only a Caterpillar thermostat and have the Cat dealer look up the thermostat for your serial number....Cat has changed temperature recommeendations recently and prefer the engines run warmer now to get more complete combustion and engine lubrication.

I have cleaned the HE both ways. Doing it in a bucket with muriatic acid gets the job done but will cost you a shirt and pair of jeans and the fumes are horrible to deal with. I much prefer to let the marina handle it with their descaling system because they have the adapters/hoses to fit the inlet and outlets on the cooling system. The chemical they use requires a license to buy since it is toxic to fish/wiildlife and humans, so I assume it is stronger that retail descalers like Barnaclean, Barnacle Buster, etc. I am sure you can make your own descaling system with some hoses, pipe fittings/clamps, a tank and a pump of some sort, but you may have to run the chemical thru the engine longer to get it as clean as a commercial rig will.
 
I'll look for the invoice tonight and post the part numbers here for you.

Kevin
 
Here is how I did it with Rydlyme. It worked great.

http://clubsearay.com/index.php?posts/886311/

This is great. I hadn't seen this write-up before. I'd like to do something similar (as I too am cursed with the do-it-yourself bug). I'd like to do what you did, but bypass the water pump. I just changed the impellers a few months ago and the port engine was a big PITA and I really don't want to remove and reinstall that impeller again. But if I bypass that, it means I'm also bypassing the fuel cooler. Do any of the technical contributors (Frank) know if the fuel coolers on these engines are known for getting clogged? Any risks to bypassing that?

Last question. Did you have any concerns with running the hose from the tranny cooler of one engine into the fuel cooler of the other engine? All the nastyness from the first engine would then get circulated into the second engine. Maybe it doesn't matter since it all gets dissolved anyway. I was just wondering if it would be better to do one engine at a time. But I guess it's easier to do them both at once.
 
I hadn’t seen it before either. It’s a great one that I’m going to keep in mind.
I see you had some minor issues with the back flow hose you used. What do you think about using the cheap clear plastic hose they sell at Lowe’s and Home Depot?
 
I have the CAT part numbers of everything I replaced when I did mine, I can send them your way if you would like.

Kevin

Hi Kevin, were you ever able to find those part numbers?
I'm getting ready to pull the Aftercoolers in a week or so. Is there a preferred hose or plug to first drain the coolant from?
 
Hi Kevin, were you ever able to find those part numbers?
I'm getting ready to pull the Aftercoolers in a week or so. Is there a preferred hose or plug to first drain the coolant from?
Hi John-
Sorry for the delay, holidays and vacations got in the way. Here are the part numbers of what I replaced:

Aftercooler Gasket - 7C-1152 (qty 2)
Aftercooler outlet hose - 7C-3615 (qty 2)
Aftercooler inlet hose - 8T-9543 (priced by centimeter, I got about 4in for each and cut it down to size once I had the old ones out to size properly)
Turbo Hose - 6I-4265 (qty 2)

I also picked up 14 (if I recall, check your specs) Gallons of ELC coolant, I can't find the part number but it's a standard thing that they will have on hand. I also got some white VHT (Very High Temperature) paint from CAT to spray the aftercoolers prior to install. They came back primed from the radiator shop, so I had to paint them.

Hope that helps, good luck with your project and ping me here if you have any questions that I can help with.
Kevin
 
This is great. I hadn't seen this write-up before. I'd like to do something similar (as I too am cursed with the do-it-yourself bug). I'd like to do what you did, but bypass the water pump. I just changed the impellers a few months ago and the port engine was a big PITA and I really don't want to remove and reinstall that impeller again. But if I bypass that, it means I'm also bypassing the fuel cooler. Do any of the technical contributors (Frank) know if the fuel coolers on these engines are known for getting clogged? Any risks to bypassing that?

Last question. Did you have any concerns with running the hose from the tranny cooler of one engine into the fuel cooler of the other engine? All the nastyness from the first engine would then get circulated into the second engine. Maybe it doesn't matter since it all gets dissolved anyway. I was just wondering if it would be better to do one engine at a time. But I guess it's easier to do them both at once.

I would think the fuel cooler would clog the most as it is first in line. It would not be hard to bypass the water pump if you wanted too. When I was finished both engines were sparkling clean. I did not have any issues doing both engines at once literally eventhing in them dissolves. But you can always do one engine at a time. Just take twice as long.
 
I hadn’t seen it before either. It’s a great one that I’m going to keep in mind.
I see you had some minor issues with the back flow hose you used. What do you think about using the cheap clear plastic hose they sell at Lowe’s and Home Depot?

The hose i used was super cheap. Like $5 for 25 ft. But it was a pain to get kink free and leak free. Wrapping the hose with a section of hose did stop the leaks. I was worried the whole time the hose would rupture, but it worked fine. A nicer hose would be better, but it has to be flexible. The clear hose from Home Depot might do the trick. If it works for you please add the details to my original post. Thanks. Pete
 
Cat has changed all the aftercooler hoses to silicon rubber hoses and the "kinky" one is now preformed with the bends already in it. Total from Caterpillar is just over $100, but those 3 hoses would be a nightmare to replace if you are not removing the aftercoolers. This isn't a place for do-overs, so I just grinned and wrote the check.............

The other observation, on saltwater boats anyway, is to replace all the hose clamps while you are replacing the hoses. I have discovered that Cat clamps are far superior to the Chinese variety you get at big box stores or the parts house.

FWIW........
 
Is there a preferred hose or plug to first drain the coolant from?
Sorry, I missed this part. Out of the heat exchanger, there is a rubber hose that attaches in to a metal tube. The metal tube is kind of U-shaped, and at the bottom of the U is a drain plug. I drained everything from that. On the port side engine I was able to drain it into a small container and then transfer that to a 5 Gal bucket. The starboard side was too limited on access, so I just drained it right in to the bilge and then pumped it out after every gallon or so to avoid the bilge pump from coming on and shooting it overboard. Not the most ideal way to do it I think, but it was the only way I could think of.

Good luck with the project, it's really not that difficult to do.
 
Thanks again for all the info. I appreciate it! I'll post an update when I do it.
 
Here's a screenshot from the cat parts site showing the heat exchanger. Part #13 is the solid tube, and 16-17 is the drain fitting. It'll be at the front of the engine, and the fitting should be at the lowest point.
 

Attachments

  • HeatExchangerDiagram.png
    HeatExchangerDiagram.png
    58.6 KB · Views: 677

Forum statistics

Threads
112,944
Messages
1,422,724
Members
60,927
Latest member
Jaguar65
Back
Top