Heat Exchanger end of life?

[32grand]

Hi,
I'm looking at the Heat Exchanger on a Lehman in my GB32, and found an area that didn't get picked up by the original survey, nor by my wandering eyes till recently. It's very corroded and I'm looking for a little advice:

- At the port-side of the exchanger, it's moist and very corroded, and has a small dent or almost-hole (see photo with circle) -- I'm not touching it much because it feels extremely fragile and ready to disintegrate if i look at it wrong. Appears to be end-of-life, replacement needed, but wanted a gut check?
(Interesting to note there's no removable end-cap on this side. I see American Diesel's do and others. Seems preferable to me.)

- On the Starboard side, mine has a different end-cap than typical, with a hose coming out to my stuffing box. I've checked with SeaFlow who advised that this will probably be reusable/screw-on to a their new replacement exchanger. I don't know exactly the flow inside these things -- It appears it's Seawater that would flow to/from the stuffingbox - but I question if there is anything "special" about the internals of my existing exchanger that would be different/incompatible with a new standard replacement unit?

- Finally looking at the Transmission cooler (green) - there is some bolt sticking up that nearly cuts into the damn heatexchanger, what's that about?! And does it appear, looking at the corrosion, that I should replace this at the same time?

Thanks for your thoughts here - this community is amazing with shared knowledge and experiences!

 

[Comodave]

Hi,
I'm looking at the Heat Exchanger on a Lehman in my GB32, and found an area that didn't get picked up by the original survey, nor by my wandering eyes till recently. It's very corroded and I'm looking for a little advice:

- At the port-side of the exchanger, it's moist and very corroded, and has a small dent or almost-hole (see photo with circle) -- I'm not touching it much because it feels extremely fragile and ready to disintegrate if i look at it wrong. Appears to be end-of-life, replacement needed, but wanted a gut check?
(Interesting to note there's no removable end-cap on this side. I see American Diesel's do and others. Seems preferable to me.)

- On the Starboard side, mine has a different end-cap than typical, with a hose coming out to my stuffing box. I've checked with SeaFlow who advised that this will probably be reusable/screw-on to a their new replacement exchanger. I don't know exactly the flow inside these things -- It appears it's Seawater that would flow to/from the stuffingbox - but I question if there is anything "special" about the internals of my existing exchanger that would be different/incompatible with a new standard replacement unit?

- Finally looking at the Transmission cooler (green) - there is some bolt sticking up that nearly cuts into the damn heatexchanger, what's that about?! And does it appear, looking at the corrosion, that I should replace this at the same time?

Thanks for your thoughts here - this community is amazing with shared knowledge and experiences!

Welcome aboard and congrats on your new boat. As to the corrosion on the heat exchanger I would ask Brian at American Diesel and see if it is possible to repair it or will you have to buy a new one.

The hose to the stuffing box is to supply cooling water and to help lubricate the stuffing box.

The transmission cooler is a routine replacement item, not exactly sure how often but since you don’t know how old it is I would just replace it. Some of them have anodes in them, that may be the screw or it could be a drain. But it looks like an anode to me. I don’t use teflon tape to seal it, usually they seal without any sealer. If it is an anode you want good electrical contact between the housing and the anode.

Good luck and have fun with your new boat.

 

[rgano]

If I were you, I would replace the lube oil cooler, the tranny cooler and the heat exchanger. The last photo is of the anode which you should be pulling and checking about every 90 days or so. They frequently swell and end up stuck in the anode well after breaking of of the brass holder. Lots of threads here on broken zincs and how to get them out - that is why you want a double-ender heat exchanger instead of the closed end you have. The heat exchanger is a double pass cooler where sea water enters one end and travels the length of the one side of the cooler before reversing at the other end. Take the end off and look closely. You will see that the rubber gasket on the end cap seals the two passes from each other. You won't have a problem with fitting up the shaft seal cooling line to the new end cap even if you were to have to get somebody to weld on a new fitting like had to do once.

When you order the replacements go ahead and get the cupro-nickle rather than the copper jacketed ones. CU-NI last longer.

While you are at this, do you know when that exhaust elbow was last changed? Look on its underside to see if any rusty water is dripping out. Should replace every five years.

 

[koliver]

The very first thing to do with that corrosion is to clean it off so that you can inspect the integrity of the metal under the corrosion deposit.
If you have ever cleaned the green off of your battery terminals, with a baking soda solution in water, you know what will happen when you use the same method on the brass heat exchanger.
Once you get to bright metal, you can see if there are holes in it. When you have it off the engine you can take it to a radiator shop and see if they can mend any holes, or if you have a level of deterioration that will require replacement rather than mending.
Good luck and keep us informed of your progress.

 

[Lollygag1]

Good luck, hopefully it can be cleaned up and is good to go as parts could be a problem.

I was just speaking to my mechanic and he stated that engine parts (and engines) are becoming difficult to get due to demand and manufacturing delays. He said Yanmar is one of the few in good shape with parts. He is starting my engine service next week so hopefully everything goes as planned.

 

[catalinajack]

I suggest you take Rich's advice. Your heat exchanger looks to be ready to pop. The trouble with taking it to a radiator shop, if you can find one, is that, if it pressure tests well, you have no idea if, tomorrow, it will fail, that it was on the very edge of failure but didn't. I replaced the exchangers on my FL120 last year and they looked a whole lot better than yours. I had no idea how old they were. I don't take chances. Same with the oil coolers. I sleep well.

If I were you, I would replace the lube oil cooler, the tranny cooler and the heat exchanger. The last photo is of the anode which you should be pulling and checking about every 90 days or so. They frequently swell and end up stuck in the anode well after breaking of of the brass holder. Lots of threads here on broken zincs and how to get them out - that is why you want a double-ender heat exchanger instead of the closed end you have. The heat exchanger is a double pass cooler where sea water enters one end and travels the length of the one side of the cooler before reversing at the other end. Take the end off and look closely. You will see that the rubber gasket on the end cap seals the two passes from each other. You won't have a problem with fitting up the shaft seal cooling line to the new end cap even if you were to have to get somebody to weld on a new fitting like had to do once.

When you order the replacements go ahead and get the cupro-nickle rather than the copper jacketed ones. CU-NI last longer.

While you are at this, do you know when that exhaust elbow was last changed? Look on its underside to see if any rusty water is dripping out. Should replace every five years.

 

[Lepke]

The green and eventual corrosion is from salt water leaks. Clean off the corrosion and nearby paint and closely inspect. Most heat exchangers can be repaired by a radiator shop. Stop the leaks and you won't get the corrosion.

If you have to replace the exchanger, there are other sources cheaper than Lehman. Here's some:https://inetmarine.com/heatexchangers-10.aspx
Custom & Stock Marine Heat Exchangers & Cooling Systems - Orca, WA
http://www.seakamp.com/
https://lencocoolers.com/

 

[SalishSeaCHB]

The green and eventual corrosion is from salt water leaks. Clean off the corrosion and nearby paint and closely inspect. Most heat exchangers can be repaired by a radiator shop. Stop the leaks and you won't get the corrosion.

If you have to replace the exchanger, there are other sources cheaper than Lehman. Here's some:https://inetmarine.com/heatexchangers-10.aspx
Custom & Stock Marine Heat Exchangers & Cooling Systems - Orca, WA
http://www.seakamp.com/
https://lencocoolers.com/

thanks for the links, Orca is just down the street! that will come in handy when I need to replace my coolers

 

[32grand]

Thanks to all for good comments.

Comodave, I likely will go ahead and replace the other oil coolers, and opt for the CU-NI main exchanger too, to keep the updates of high quality. Agree with your note about not using (much if any) teflon tape on zincs to help the electrical bond.
Catalinajack thanks for the clarity.

Rgano, interesting point about the exhaust elbow needing to be looked at/maintained. I didn't know it could be as low as five years. It does have a little different finish on the bottom, like the red paint getting heated off/dull, but i don't yet see active leaks that i can tell. Will setup some test cloths and be on the lookout to see though. In the top most photo above, there is some pretty dark oil there -- I'm assuming that is not related to the exhaust system, would you agree?
And you mentioned "You won't have a problem with fitting up the shaft seal cooling line to the new end cap even if you were to have to get somebody to weld on a new fitting like had to do once."
I'm super curious about Welding a new fitting on an end cap, like you mention. That seems painful, hoping I can re-use the same cap for sure. But I suppose for somebody with the right tools it's not bad, assuming they know specifics about the right metals to use for this saltwater environment. Heck, maybe it's so close to the anode it wouldn't matter that much, hmm.
(Reference of an end-cap itself: https://inetmarine.com/sk3400cendcapkitfor418diaheatexchanger.aspx)

Thanks for the links Lepke. I'll add Fred Warner and American Diesel's to the list of Heat Exchanger suppliers.

Ford Lehman 120 Heat Exchanger 2C218 Copper-Nickel Marine Diesel Engine
https://www.fredwarner.net/product/...2c211-marine-diesel-6-cylinder-engine-copper/

(As an aside, that SeaKamp.com website -- holy guacamole, that website gives me pause when thinking of using their product. I mean talk about about need some Replacement Parts, that site sure does lol.)

So,
I guess I'll drain it, scrub the corrosion just to see what exactly the state is, and order the new bad boys too. I'm stuck at the dock for a while it seems, but maybe I'll take her out for a couple more runs first, just to push my luck. Heck, i've got TowBoatUS right?!

I'll be sure to post back photos - it's great to build the TF site with outcomes/solutions for future people. Which is ironic to say given these boats are alreay 40+ years old!