Out cruising - raw water leak in FL120 oil cooler

[socalrider]

Quick summary to conclude this thread: the JB Weld fix got me back to SD without issue, no visible crystals forming - agree it's probably good for another 10 years.

That said, I'm going ahead and replacing all four coolers with new parts from American Diesel. They have them in Copper for $98 (1200-1500hr life) or Cu/Ni for $120/ea (1700-2000hr). Going with the latter. They didn't recommend going to the trouble of re-plumbing for freshwater, and said that switching both the transmission and oil coolers would exceed the capacity of the freshwater heat exchanger, so I'm keeping it simple. Seems like a worthwhile place to spend $500.

 

[MVDarlin]

Clean it with sandpaper then JB Weld epoxy as a get home repair.

 

[mickand]

Ford Lehman 120's will normally have sausage type raw water cooled engine oil and transmission oil coolers. Oil and transmission coolers are often an overlooked mtce. item and when they fail you may not realize, particularly the transmission cooler which has the fluid running through it under pressure so the oil just disappears out the exhaust. I have gained this knowledge through experience. Lehman coolers are inexpensive so I now replace them every four years. Probably overkill but beats a $6500 transmission rebuild.

 

[crowleykirk]

These old Fords are my babies

We were the Ford Lehman dealer in Newport Beach Ca. Know these like th back of my hand, well, what I can remember

As for the oils and trans coolers. We ALWAYS recommended just replacing them every 4 years. No matter what. And have spares on board, always. Pretty obvious what happens when these go bad and it can happen often.

I would not call that a leak. That is. A bad cooler. Simple as that. Now, if they get so much build up you can’t clean them with a 1/8 th dowel you can take them off and clean them in keratin acid. Pool acid. Well ventilated and rubber gloves.

Same for your rear heat exchanger.

Do not try to add years to a cooler, just replace it. The large rear one should last much longer, 6 to 8 years in most cases. Just keep it clean as well.

Best of luck,

Kirk

 

[Whodgins]

Raw water cooled engine oil coolers are common on older engines, especially gassers. Mine are done that way (water off the water pump goes to the trans cooler, then engine oil cooler, then heat exchanger). The Lehman is an old enough design that I wouldn't be surprised if it's done the same way.

Raw water coolers are standard on marine versions of most Gardner engines and we have one of these cast bronze beauties on our 6LXB. They use a "dimpled" brass tube with the engine oil flowing through it on the inside and sea water pulling out the heat on the outside before continuing on to our other heat exchangers (engine coolant and CPP oil) and then on to the wet exhaust elbow.

Works very well and Gardner engines run quite a bit cooler than most modern diesels, we tend to sit about 60-62C / 140-144F when underway. On interesting consequence of this is that the fresh water/antifreeze cooling system on these LX engines runs at atmospheric pressure, no pressure required which keeps things even more simple and easy to maintain.

 

[ronobrien]

Another one for the TF brain trust

After an extremely trouble free summer of Channel Islands cruising I noticed the attached pic - salt crystals forming on the aft seal of my port engine oil cooler.

I’m at Cat Harbor now, planning on motoring back (10hrs) to San Diego on Friday. Unfortunately I’m not carrying a spare. Trying to figure out the best path forward. I’ve not pulled apart one of these so proceeding with caution.

1. Think it’ll make the trip back? Or,
2. Possible to repair locally? Or,
3. Should I try and get a replacement in the next 24 hours?

Edit: oil looks good. I am losing a bit (maybe a quart every 10 hours or so) but no evidence that water is getting into the oil.

The biggest concern is water in the oil. That could damage the bearings pretty quickly. An external leak is not a concern as long as you are getting some cooling. You could bypass the water around the cooler and just take it easy. Watch the temp(s). Again, water in the oil is a major concern.