Transmission Cooler Cleaning

[larman]

So my Cummins 6bta has been running a little hot. I just checked the transmission coolers and they were clogged. One had a zinc stuck in there. What is the proper way to clean these. Radiator shop or can I cap of fluid side and soak in barnacle buster?

 

[sunchaser]

So my Cummins 6bta has been running a little hot. I just checked the transmission coolers and they were clogged. One had a zinc stuck in there. What is the proper way to clean these. Radiator shop or can I cap of fluid side and soak in barnacle buster?

How old is the cooler? Usually these are a small cooler and not too expensive. Along with others I consider them a throw away item after a decade or so. Check out Seaboard for a price.

 

[larman]

How old is the cooler? Usually these are a small cooler and not too expensive. Along with others I consider them a throw away item after a decade or so. Check out Seaboard for a price.

Motors are 2003 vintage with 750 hours on them. I would like to clean them.

 

[Cigatoo]

That cooler if original is 20 years old. This guy is a well informed Cummins Tech.

"The couch engineers that write maintenance intervals base everything on the engine hour meter – This is Completely Ridiculous! You have had seawater inside your engines cooling system for how many years? 3, 5, 7? and do you really think “Mother Nature’s” destructive work stops when you turn off the key? Think again…"

Read the whole article here.
https://www.sbmar.com/featured-article/marine-age-the-real-age-of-a-marine-diesel-engine/

 

[Fletcher500]

You can clean it yourself, or if take it to a radiator shop and they can pressure test as well. I only have 1 engine, so I take all 3 of my coolers to a reputable shop for the peace of mind, especially the after cooler which can cause bad things to happen if the tube bundle is compromised.

I posted on Tony's (SBMAR) website awhile back about cleaning my Gyro heat exchanger; his reply:

"Commonly available Pool acid (HCL) mixed 10:1 with water is what we have using for over 3 decades..Totally safe, easy to get, cheap, and 100% safe."

Also, I attached a photo of my Trans cooler after only 2 years. It's the smallest of the 3 coolers on my QSB and sits at the lowest point so always full of seawater hence the CaCO3 buildup. The other 2 coolers had 0 tube blockage.

As you probably know, many boaters ignore these coolers because its $ to take to good rad shop and a PITA to get them off but it reminds of the old Fram oil filter commercials - "pay me now, or later.."

 

[DavidM]

A radiator shop is a good solution. But you can easily clean them yourself. Take both endcaps off and run a brazing rod, gun cleaning rod or similar to push out the big zinc pieces.

Then set the exchanger upright on a rubber mat and pour a 50/50 Barnacle Buster, CLR or similar solution down the open end. Let it sit for a couple of hours and then thoroughly flush with water.

David

 

[larman]

Do you know what size gun cleaning rod I might need or are they just standard thickness?

 

[Juliet 15]

A radiator shop is a good solution. But you can easily clean them yourself. Take both endcaps off and run a brazing rod, gun cleaning rod or similar to push out the big zinc pieces.

Then set the exchanger upright on a rubber mat and pour a 50/50 Barnacle Buster, CLR or similar solution down the open end. Let it sit for a couple of hours and then thoroughly flush with water.

David

This (above).



I'll take heat exchangers to a pro for pressure testing every 3 to 5 years, but I've rodded out heat exchangers of all types for many years, including on a pair of Cummins 6BTAs. I think it's a 1/8 inch rod.



As an aside, I don't know that your overheat issue is bcs of the tranny heat exchanger. My 6BTAs would start getting warm when the big engine oil heat exchangers needed cleaning out. That was actually the indicator for me to clean them.


My 2 cents.

 

[larman]

Think I will take them to the radiator shop for the cleaning. Thanks all for the replies.

 

[larman]

A radiator shop is a good solution. But you can easily clean them yourself. Take both endcaps off and run a brazing rod, gun cleaning rod or similar to push out the big zinc pieces.

Then set the exchanger upright on a rubber mat and pour a 50/50 Barnacle Buster, CLR or similar solution down the open end. Let it sit for a couple of hours and then thoroughly flush with water.

David

David, by the way this is the boat that you helped me move from Baltimore to Long Island in 2019.

 

[firehoser75]

larman,
It is a very good idea to take all of your raw water cooling components to the rad shop for cleaning and PRESSURE TESTING!
Pressure testing is very important, as you don't want saltwater to "get into" areas it shouldn't!!! Such as in the air intake (aftercooler leak), or in the antifreeze (engine HX leak), or in the tranny fluid, etc. All of this work is relatively easily done by a good DIYer (building your own testing setup). These are regular maintenance items (every 4-5 years or so.

If you have what is often the standard stock exhaust system with original hoses, it is well past time to service that as well. The exhaust system may need a total redesign (mine did), as often they are designed and installed in such a way as they are "doomed to fail" (per what Tony Athens shows on his site (sbmar.com). If yours are like mine was, when it fails (not if, but when) it could easily allow saltwater to enter into your turbo and maybe even into your exhaust manifold, necessitating expensive repairs. Check it out. Good info available for free at sbmar.com under Tony's Tips and on his forums.

Good luck.

 

[jungpeter]

That cooler if original is 20 years old. This guy is a well informed Cummins Tech.

"The couch engineers that write maintenance intervals base everything on the engine hour meter – This is Completely Ridiculous! You have had seawater inside your engines cooling system for how many years? 3, 5, 7? and do you really think “Mother Nature’s” destructive work stops when you turn off the key? Think again…"

Read the whole article here.
https://www.sbmar.com/featured-article/marine-age-the-real-age-of-a-marine-diesel-engine/

Hi Cigatoo. Careful here. You've provided a link to an article included in the sbmar web site. You have alluded to the author ("this guy") as a well informed Cummins Tech, yet the article itself is not attributed. So who actually authored this piece? Are you assuming Tony Athens authored this piece? If so, while I respect his opinions, I am loathe to broad-brush this written work across the board. In this case, if you're suggesting that a 20 year old transmission cooler must be replaced, I'm afraid you're conflating apples with oranges.

All the pictures in the article, and the overall gist of the article refer to mixed-metal (aluminum and copper-based) aftercoolers, which are NOT the same kettle of fish as the transmission cooler from the original poster (OP). The OP stated, and is holding a cooler that appears to be a bronze casting, containing a (probably) cupro-nickel tube bundle, with no contact with hot charge air. These coolers have a SIGNIFICANTLY longer lifespan than the mixed-metal aftercooler displayed in the sbmar URL. And while I agree that lack of maintenance of ANY marine item results in a shortened lifespan, I suggest that the OP's transmission cooler, with correct and routine maintenance, can and will last the lifetime of the original engine.

I confess to be somewhat aghast that Cummins uses aluminum in a context that mixes seawater with anything hot, like charge air in an aftercooler. And while 32,000 hours in 10 years of service for the referenced engine is impressive, I expect proper, routine preventative maintenance of ALL aspects of that engine were the key.

And I'm all ears if anyone can provide a better metric for PM than age or engine hours.

Regards,

Pete

ps-to the Original Poster larman-yup, take the cooler to a radiator shop for cleaning, pressure testing, and inspection. Then do it again every 5 years down the road. Money well spent.

 

[jleonard]

Do you know what size gun cleaning rod I might need or are they just standard thickness?

I used to use a .22 cal rod/brush setup. And then I'd drizzle muriatic acid thru it then a good water flush.

 

[sunchaser]

Larman
Is this a twin engine boat?

 

[sunchaser]

to the Original Poster larman-yup, take the cooler to a radiator shop for cleaning, pressure testing, and inspection. Then do it again every 5 years down the road. Money well spent.

Can a transmission cooler be tested at a "normal" radiator shop? I ask because it seems with the oil pressure inside a ZF transmission running several hundred PSI that the test pressure should be well above what an automotive radiator, marine engine raw water heat exchanger or after cooler sees for pressure.

BTW, Seaboard's discussion on transmission coolers seems spot on as it calls out "wrong alloy" imposters and says stick with a proven CuNi high pressure design.

 

[bshanafelt]

I vote for replacing the cooler.

I have the same configuration 5.9, although mine is a mid 90s vintage.

About 10 years in I thought I would remove the drain plug on this cooler as part of winterization. Imagine my horror when the plug broke off in place because it was rotting from the inside out.

You can buy a brand new cupronickel cooler at fisheries for about $150-$200.

This for me is now a regular five year swap it, and dump the old one scenario

The idea of salt water circulating through my tranny is enough to keep me up at night

 

[larman]

Larman
Is this a twin engine boat?

Yes

 

[sunchaser]

Yes

Two coolers need cleaning then? As noted by others your other HXers and coolers may well be ready for an R&R. If you've not done so a read through Seaboards site on Cummins heating system maintenance may prove illuminating.

 

[Cigatoo]

Hi Cigatoo. Careful here. You've provided a link to an article included in the sbmar web site. You have alluded to the author ("this guy") as a well informed Cummins Tech, yet the article itself is not attributed. So who actually authored this piece? Are you assuming Tony Athens authored this piece? If so, while I respect his opinions, I am loathe to broad-brush this written work across the board. In this case, if you're suggesting that a 20 year old transmission cooler must be replaced, I'm afraid you're conflating apples with oranges.

All the pictures in the article, and the overall gist of the article refer to mixed-metal (aluminum and copper-based) aftercoolers, which are NOT the same kettle of fish as the transmission cooler from the original poster (OP). The OP stated, and is holding a cooler that appears to be a bronze casting, containing a (probably) cupro-nickel tube bundle, with no contact with hot charge air. These coolers have a SIGNIFICANTLY longer lifespan than the mixed-metal aftercooler displayed in the sbmar URL. And while I agree that lack of maintenance of ANY marine item results in a shortened lifespan, I suggest that the OP's transmission cooler, with correct and routine maintenance, can and will last the lifetime of the original engine.

I confess to be somewhat aghast that Cummins uses aluminum in a context that mixes seawater with anything hot, like charge air in an aftercooler. And while 32,000 hours in 10 years of service for the referenced engine is impressive, I expect proper, routine preventative maintenance of ALL aspects of that engine were the key.

And I'm all ears if anyone can provide a better metric for PM than age or engine hours.

Regards,

Pete

ps-to the Original Poster larman-yup, take the cooler to a radiator shop for cleaning, pressure testing, and inspection. Then do it again every 5 years down the road. Money well spent.

It’s all about what the owner is comfortable with. I tend to over do PM. I spent 40 plus years working with gasoline and Diesel engines in cars and equipment. Nothing needs replacement until it breaks. “Significantly longer” has gotten me into trouble more than once. Some people don’t give it a second throught and come out just fine. Me not so much. Lol.

 

[alormaria]

I'm rippin' the MOFers out right now! Gettin' them boiled and tested.



Really. Replacing the hoses too.



Every 46 years whether they need it or not.



It's only money.

 

[firehoser75]

To add to my earlier comments regarding the exhaust system, especially the elbow: even a high quality stainless steel exhaust elbow has a service life. Mine lasted about 15 years, and then suffered pin hole corrosion, where the water spray did not cool the rubber exhaust hose adequately anymore. If the corrosion had gone on "undetected" the following are potential issues that could or would develop (on my Cummins 6BTA): saltwater ingested by the turbo; saltwater entering the engine via the exhaust manifold; damage to the rubber exhaust hose (from overheating) possibly resulting in failure and hot saltwater and engine exhaust gases entering my bilge and ER, etc.
If not for the fact that I had recently installed an overheat alarm on the exhaust hose (right after the elbow), (a Borel alarm), I would not have known there was a problem!! The engine was not overheating at all, just the exhaust hose. I highly recommend this type of "overheat" alarm. Inexpensive, easy to install, and it will alert to an impending overheat BEFORE damage is likely to occur.
If your exhaust elbow looks like mine (the stock "white" Cummins elbow), you could be on borrowed time. I attached a photo of the new "dry" exhaust where the water is injected well below the turbo to avoid potential water ingestion and/or backflow. Addressing this before failure (while not cheap) could save you thousands.

 

[Dwk]

I’m joining Alormaria! We have had zero cooling problems and no unwanted fluids showing up and that’s how we like it, no surprises. I replaced all the oil lines 3 years ago but never tested the oil cooler, It’s time for inspection and maintenance.

 

[larman]

To add to my earlier comments regarding the exhaust system, especially the elbow: even a high quality stainless steel exhaust elbow has a service life. Mine lasted about 15 years, and then suffered pin hole corrosion, where the water spray did not cool the rubber exhaust hose adequately anymore. If the corrosion had gone on "undetected" the following are potential issues that could or would develop (on my Cummins 6BTA): saltwater ingested by the turbo; saltwater entering the engine via the exhaust manifold; damage to the rubber exhaust hose (from overheating) possibly resulting in failure and hot saltwater and engine exhaust gases entering my bilge and ER, etc.
If not for the fact that I had recently installed an overheat alarm on the exhaust hose (right after the elbow), (a Borel alarm), I would not have known there was a problem!! The engine was not overheating at all, just the exhaust hose. I highly recommend this type of "overheat" alarm. Inexpensive, easy to install, and it will alert to an impending overheat BEFORE damage is likely to occur.
If your exhaust elbow looks like mine (the stock "white" Cummins elbow), you could be on borrowed time. I attached a photo of the new "dry" exhaust where the water is injected well below the turbo to avoid potential water ingestion and/or backflow. Addressing this before failure (while not cheap) could save you thousands.

I think mine is a bit different. Where did you purchase the borel alarm.

 

[bshanafelt]

Fwiw when I replaced my first cooler, I also added an inline zinc holder just upstream of the unit

My cooler does not have a place for a zink to live thus the addition

The zinc holder comes with a post to tie into the bonding circuit, so electrically it actually does something since it is insulated with rubber hose on each side

Part of a maintenance is replacing that zinc once a year with the other agent sink in the engine HE

I have no idea if it’s really doing anything but seemed like a good idea at the time

 

[Greg QS]

This (above).



As an aside, I don't know that your overheat issue is bcs of the tranny heat exchanger. My 6BTAs would start getting warm when the big engine oil heat exchangers needed cleaning out. That was actually the indicator for me to clean them.


My 2 cents.

The tranny cooler is in the cooling system that flows through the main heat exchanger. Blockage in tranny or fuel coolers will definitely block overall flow and reduce the cooling capability of the main heat exchanger. All exchangers should be Cleaned at the same time. fuel, tranny, and main heat exchanger.


I am doing a full service on my cummings qsm11 engines. the coolers were 350 each boiled in ultrasonic tub , pressured tested. and looked bran new when returned. Time to paint.

 

[firehoser75]

I think mine is a bit different. Where did you purchase the borel alarm.

Direct from the manufacturer: https://www.borelmfg.com/products/
$149 for 2 alarms and small indicator panel with built in buzzer. No affiliation, just a customer.
Your exhaust does look a bit different than what mine was, but just be aware, that the elbow is a part that does need periodic replacement, especially if the raw water injection point is level with or above the turbo (or exhaust manifold if no turbo). When the internal "shower head" no longer works as designed, the rubber exhaust hose (or fibreglass parts if used) can overheat with no obvious warning. I have been in contact with several owners who have had their exhaust hoses delaminate as a result of this overheating without any indication on engine gauges.
Just trying to help readers avoid a potential problem

 

[ssurabus]

The tranny coolers are the most inexpensive of the bunch. I had to replace mine due to condition, but I'm a big fan of running barnacle buster through the system periodically and trying to take care of the coolers. Ignoring them until you have a problem won't end well- and predictably it will be at bad time. While an acid flush doesn't replace a proper cleaning (remove, disassemble, pressure test) it goes a long way and generally mitigates any creeping temps. Regarding the stuck anode in OP's cooler to prevent them from being stuck/broken in the cooler, use the current generation rapid extraction zincs (REDZn). I am the designer and have used them for many years on my boat and others without any of the hassles of broken/stuck zincs.

 

[Captain Doug]

I cleaned mine with a #12 bare copper wire on my cordless drill. Needed the flexibility to get the outside tubes cleaned. Pressure tested the water side with an automotive cooling system tester at 20lbs for an hour. Reinstalled, no issues. Lots of barnacles and small rubber pieces.