Descaling / clearing exchanges, and coolers on CAT 3126

[Tom Coombs]

Folks;

New to diesel. Have a 400DB with 2 Cat 3126 engines, each with about 1400 hours. No written history on the engines, but it's obvious that they have been well maintained.

I have a diesel tech who has come recommended from other owners in our marina, and in a recent discussion with him, he has recommended removing the transmission coolers for inspection and descaling as an indicator of the health of the heat exchanger and aftercooler, and as a basis for removing and descaling those also.

A different gentleman has suggested that to remove those coolers is expensive and unnecessary and that a much better alternative to removal is to set up a flushing loop and flush for an extended period of hours with barnacle buster or similar. I watched the process on YouTube and it does seem to be pretty straightforward.

So the question is, remove or not remove, and are their any ill effects to flushing with Barnacle Buster?

Thanks for your help and advice in advance

TC.

 

[The Bill Collector]

I have used Rydlyme 2 x now.... With great results, the only caveat is to do this before zinc replacement as the stuff will eat your zincs. Also, it easy to view transmission heat exchanger end caps and see how much scaling is built up in there.

 

[Tom Coombs]

I have used Rydlyme 2 x now... With great results, the only caveat is to do this before zinc replacement as the stuff will eat your zincs. Also, it easy to view transmission heat exchanger end caps and see how much scaling is built up in there.

Thanks for the product recommendation. The diesel tech warned that the flushing products caused damage to some of the metals if they weren't neutralized properly after the flush. Is that a big concern?

 

[JVM225]

I have used Rydlyme 2 x now.... With great results, the only caveat is to do this before zinc replacement as the stuff will eat your zincs. Also, it easy to view transmission heat exchanger end caps and see how much scaling is built up in there.

When you connected your loop, where did you connect the hose to go in to the system and where did you have it exit?
Did you run it backwards?

 

[The Bill Collector]

When you connected your loop, where did you connect the hose to go in to the system and where did you have it exit?
Did you run it backwards?

I had the Rydlyme guy onboard doing it... Sorry.

 

[fwebster]

First, coolers are assembled using solder. Muriatic acid eats everything organic and will decay already weak solder joints. Only use a cleanser that you can verify its contents. If it contains Muriatic acid, I wouldn't use it. Instead, look for a cleanser based on Phosphoric acid which is much more user and soft metals friendly.

Sorry, I don't use either Rydlyme or Barnaclean because I have not ben able to verify their contents.....they may be fine, but they aren't very forthcoming with the chemicals they use. I use a product from Kleen Strip called Prep-n-Etch. It is a surface preparation for painting metals, available in Home Depot for about $18/gal and is a 20% solution of Phosphoric acid.

Your mechanic is correct.......the transmission oil coolers are an excellent tell-tail of the heat exchanger condition on Caterpillar engines. They are in the direct flow path of the seawater that cools the heat exchangers and will show the same degree of fouling that you would expect to see in the heat exchangers.

The "different gentleman" on your dock that told you the transmission oil coolers are expensive to remove obviously has never done or had it done it on Cat 3126's. There are 2 hydraulic fittings to remove, neither of which are under pressure, a 1-1/4" hose clamp on either end and a mounting cradle with 2 bolts that must be removed....all of which takes about 15 minutes. Once off the boat, you can inspect the inside of the tube bundle and go about cleaning them with acid if you need to.

The other primary reason for removing the transmission oil cooler is to have them pressure tested or replaced. A transmission oil cooler does not have an infinite life. After about 15 years, it is wise to check or replace them. If you get a leak in the tube bundle inside the transmission oil cooler, you will fill the transmission with seawater and. that is a "terminal event" for the transmission unless you catch it and flush the gear box immediately.......like within minutes.

Many marinas that service larger boats have an engine flushing device and all the hose adapters needed to run a descaler there the cooling system. Most owners find it more cost effective to hire this work done by a service center that is already equipped and stocks the hose adapters and descaler. It takes 3-4 hours per engine so it isn't terribly expensive since the mechanic can be doing other things while the descaler is running. The other factor on Caterpillar 3116/3126 engines is that their cooling systems have a lot of excess capacity and you should only need to descale the engines every 5-7 years.

The only way to tell if you really need to clean the cooling systems is to run the boat with normal loading at 2400 rpm. If the temperature rises about 185˚ and keeps rising until you pull the throttles back, and then falls to below 185˚, then you need to clean the heat exchangers.......and don't exceed 185˚ until you clean the heat exchangers.

Hope that helps........

 

[The Bill Collector]

The only way to tell if you really need to clean the cooling systems is to run the boat with normal loading at 2400 rpm. If the temperature rises about 185˚ and keeps rising until you pull the throttles back, and then falls to below 185˚, then you need to clean the heat exchangers.......and don't exceed 185˚ until you clean the heat exchangers.

Hey Frank, I replaced me T-stats last year and CAT is now calling for 195* and that is what is now installed in my boat.

 

[Golfman25]

My former sales rep. used to rep Rydlyme. He sold to all the steel mils and was working on the gambling boats in the area. He gave us some to do our heat exchangers on our equipment. It's pretty good stuff. Easy to use, environmentally safe, etc. It's concentrated so a little goes a long way.

 

[The Bill Collector]

My rep. sells it to the Naval shipyard here in 55-gallon drums...

 

[Tom Coombs]

Frank et al;

Thanks for your detailed replies....we ran the boat back from the PO just a week or two back and the temps didn't get above 185 (at the helm) all the way down the intra-coastal in South Florida (read 80+' water) and at idle was in the 165-170 range.

The Transmission coolers are off. As you say, it took about 15 minutes. They didn't look great and didn't look terrible either and they certainly were not blocked up. He has taken them to clean, pressure test and paint.

The "different gent" I mentioned runs a mom and pop maintenance service right here from the Marina. He was referring to the fact that removing ALL of the other exchangers / aftercoolers etc. was expensive, (I have a quote in hand for the two sides of about $4K to do all of that work and a couple of other items if needs be). He has the apparatus and chemicals to provide a flushing service for the engines.

On a separate note, we found the source of an oil leak today; from one of the governer seals, so that will need to be taken care of and it looks like we may need to rebuild the turbo on the stbd side because of excessive play, with the port side not far behind. An engine run will tell us if we need to do that now or if we have a little time.

In any case, we are baselining the two engines and I budgeted some spend to get to a good schedule.

Thank you again, the information from this board has been invaluable every step of the way through our journey so far.

 

[mrsrobinson]

Recently went thru this journey. I did each cooler seperately: https://tinyurl.com/2s38r4cw

 

[ttmott]

Frank et al;

Thanks for your detailed replies....we ran the boat back from the PO just a week or two back and the temps didn't get above 185 (at the helm) all the way down the intra-coastal in South Florida (read 80+' water) and at idle was in the 165-170 range.

The Transmission coolers are off. As you say, it took about 15 minutes. They didn't look great and didn't look terrible either and they certainly were not blocked up. He has taken them to clean, pressure test and paint.

The "different gent" I mentioned runs a mom and pop maintenance service right here from the Marina. He was referring to the fact that removing ALL of the other exchangers / aftercoolers etc. was expensive, (I have a quote in hand for the two sides of about $4K to do all of that work and a couple of other items if needs be). He has the apparatus and chemicals to provide a flushing service for the engines.

On a separate note, we found the source of an oil leak today; from one of the governer seals, so that will need to be taken care of and it looks like we may need to rebuild the turbo on the stbd side because of excessive play, with the port side not far behind. An engine run will tell us if we need to do that now or if we have a little time.

In any case, we are baselining the two engines and I budgeted some spend to get to a good schedule.

Thank you again, the information from this board has been invaluable every step of the way through our journey so far.

Baselining is essential for best reliability - obviously. Get it done especially if there are no documented maintenance records. Having the boat as reliable as reasonable really makes the use of it so much more enjoyable. The second component is to surround yourself with quality services that you can trust and stick with them. I think this is an evolution thing of hard knocks for most. But, there is nothing like having the mechanic that has been working on your engines for years on tap when you are having issues 200 miles away. To my point - we were in the Exumas several months ago and the solon HVAC went down. I texted my HVAC guy who has been working on my boats for years on a sunday; he was out fishing. He took the time to walk me through some TS and find the issue which was the connector behind the controller. I'm very blessed to be surrounded by the best talent who put up with my OCD but with that came the rotten fruit that I had to walk off the dock also.

 

[mrsrobinson]

Absolutely agree, I wish I could find a diesel mechanic, I've been ghosted five times though, which is why in this case I did the work myself and will later baseline.

 

[Saverio]

Recently went thru this journey. I did each cooler seperately: https://tinyurl.com/2s38r4cw

Just watched your videos very informative... Great Job!!!!

did you get your new hose at Cat? are we talking about $100 per engine?

 

[mrsrobinson]

Just watched your videos very informative... Great Job!!!!

did you get your new hose at Cat? are we talking about $100 per engine?

Yes, local CAT dealer. Price was much less than I thought it would be, reasonable.

 

[Saverio]

Cool
I'm still contemplating what to do i'm at 950 hours. do i pull the aftercooler or just flush them?

 

[mrsrobinson]

What I did was to get me back on the water and salvage the season. I plan to baseline this winter hopefully. I am at 1050 hours. My challenge is finding a diesel mechanic (the easy part) who will show up (the hard part).