CAT 3126 HEX

fwebster said:
Who was that Bennett? Seems like I've heard it before!

Cat engine have a bunch of hose clamps on them. When you move a boat from South Florida to someplace that gets freezing temperatures, hoses contract with the first cold snap. Before you tear apart your cooling system looking for a leak, try tightening all the hose clamps near and above the heat exchanger.

I bought my boat when she was 6 mopnths old/35 hours on the engines. THe boat was ordered, built and delivered in May. The next January, Panama City had a 3 day cold snap with temps not getting over 32˚. My next trip down I found a bilge with puddles of red Cat ELC everywhere. I spent a morning wiping every hose clamp with a paper towel; found several wet and retightened every hose clamp I could get to. That was in 1997 and I haven't had a coolant leak since.
Click to expand...

First thing I did was wrap some paper towels around anything I thought might be producing a leak. The biggest offender was the cap on the expansion tank, and that wasnt producing a whole lot. My thinking now is that when I have opened the tank, a small amount ran down and filled the voids in the paint on the HEX, and when I got back there to clean things up, it looked worse than it really is. I'm still going to pressure test it. It could also be as you describe, loose clamps so I'll check those as well. Like I said, I watched the coolant levels and they were rock solid all summer. May be she's a FL girl at heart and doesnt like the cold!
 
I borrowed a radiator pressure test setup from Advanced Auto Parts and tested the coolant side today. They charged my CC $250 but will refund it all as long as I bring it back within 45 days...pretty fair deal! I’ll be buying some more odds and ends so they get a little payback.

I put 10 psi on the coolant system. The needle moved almost inperseptibly over 30 minutes. I think that was a ghost I was chasing.

Based on Franks info, I think it’s just cold enough to cause a little leak.

I’ll continue to monitor the HEX and follow Carter’s suggestion to clean it up and get some paint on it.
 
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fwebster said:
Who was that Bennett? Seems like I've heard it before!

Cat engine have a bunch of hose clamps on them. When you move a boat from South Florida to someplace that gets freezing temperatures, hoses contract with the first cold snap. Before you tear apart your cooling system looking for a leak, try tightening all the hose clamps near and above the heat exchanger.

I bought my boat when she was 6 mopnths old/35 hours on the engines. THe boat was ordered, built and delivered in May. The next January, Panama City had a 3 day cold snap with temps not getting over 32˚. My next trip down I found a bilge with puddles of red Cat ELC everywhere. I spent a morning wiping every hose clamp with a paper towel; found several wet and retightened every hose clamp I could get to. That was in 1997 and I haven't had a coolant leak since.
Click to expand...

That was my friend and mentor Frank Webster....

One of the first thing I did while getting to know my bilge was to take a nut driver and tighten all hose clamps....

Bennett
 
dtfeld said:
I borrowed a radiator pressure test setup from Advanced Auto Parts and tested the coolant side today. They charged my CC $250 but will refund it all as long as I bring it back within 45 days...pretty fair deal! I’ll be buying some more odds and ends so they get a little payback.

I put 10 psi on the coolant system. The needle moved almost inperseptibly over 30 minutes. I think that was a ghost I was chasing.

Based on Franks info, I think it’s just cold enough to cause a little leak.

I’ll continue to monitor the HEX and follow Carter’s suggestion to clean it up and get some paint on it.
Click to expand...

That’s great news! I usually go around and check clamps when I’m doing the zincs.
Going to be ordering the zincs early next month and changing them before I launch. I hate that job!
 
JVM225 said:
That’s great news! I usually go around and check clamps when I’m doing the zincs.
Going to be ordering the zincs early next month and changing them before I launch. I hate that job!
Click to expand...

I pulled mine yesterday in advance of trying to descale the HEX. I have 1 of 10 stuck in the aftercoolers and 1 in the starboard HEX. Of course its the one buried back behind everything....grrrrr.
 
dtfeld said:
I pulled mine yesterday in advance of trying to descale the HEX. I have 1 of 10 stuck in the aftercoolers and 1 in the starboard HEX. Of course its the one buried back behind everything....grrrrr.
Click to expand...

I’m hoping for a string of warm days in early March so I can spread the removal aggravation over a couple of days. That’s what I did last year. If for some strange reason I get lucky (which I seriously doubt will happen), and none get stuck or break off on me, it will be a pleasant surprise.
I did them a second time in the mid season last summer and although it’s better than doing them once a year it’s still a PIA job.
At least now I know what tools and supplies to bring with me to tackle them.
 
dtfeld said:
I pulled mine yesterday in advance of trying to descale the HEX. I have 1 of 10 stuck in the aftercoolers and 1 in the starboard HEX. Of course its the one buried back behind everything....grrrrr.
Click to expand...
I got a 90° adapter for my drill and using left handed drill bits, I was able to remove all my stuck ones - I had a heck of a lot more than 2 stuck my first time!!
 
dtfeld said:
I pulled mine yesterday in advance of trying to descale the HEX. I have 1 of 10 stuck in the aftercoolers and 1 in the starboard HEX. Of course its the one buried back behind everything....grrrrr.
Click to expand...
I got a 90° adapter for my drill and using left handed drill bits, I was able to remove all my stuck ones - I had a heck of a lot more than 2 stuck my first time!!
 
carterchapman said:
I got a 90° adapter for my drill and using left handed drill bits, I was able to remove all my stuck ones - I had a heck of a lot more than 2 stuck my first time!!
Click to expand...

Among other things, I bring along my regular drill, my right angle drill and my easy out kit with left hand drill bits.
I’m wondering if aluminum anodes might be less likely to deteriorate and get stuck in the same way that the zinc ones do.
 
JVM225 said:
Among other things, I bring along my regular drill, my right angle drill and my easy out kit with left hand drill bits.
I’m wondering if aluminum anodes might be less likely to deteriorate and get stuck in the same way that the zinc ones do.
Click to expand...

I can answer that. NO!
 
Removed the sea water pumps today (well almost, have 1 bolt to go on the starboard engine) and opened up the HEX ends. Port side was very clean, only one tube on the bottom clogged up. However the starboard had various pieces and parts and a fair amount of build up. It also was dripping some coolant...

Question. Once I have the end cap off, can I pull the tube bundle out for cleaning or is there more to it? I have a set of O-rings, the smaller one that goes in the cap and a larger diamenter, that I expect seals the coolant from the sea water side.

I've never had one apart, so looking for some directions.

Port HEX..pretty clean :)

20190219_141357.jpg


Starboard side debris

20190219_153114.jpg


Starboard side dripping coolant, and with a fair amount of build up and debris.

20190219_151141.jpg
 
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Pulled the heat exchanger off the starboard today. Worst part was getting the ELC out, but I was able to get two 5 gallon buckets under the drain on that side. The port will not be that easy.

I soaked the end pictured above in Barnacle Buster and it cleaned up very nice. I'm going to scrape as much old paint off and rust off the shell, hit it with Ospho and repaint. I also have all new o-ring seals. I don't think it really needs much more than that.

However, having a hard time getting the bundle out of the shell. Anybody ever separate ? Advice?

Once I separate, I'll get a much better inspection done, but from what I see this thing is pretty solid

Would anybody take the time and money to take it to a shop for further service??



20190228_183838.jpg
20190228_183849.jpg
 
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I finally pulled the bundle out of the shell. The seals are all compression o-ring, and the one holding the bundle in must be original, had a pretty good grip on it. I used two plaster knives to protect the mating surfaces and gently pried the cap off. It came, but slowly.

Looking at all the pieces, the look to be in good working order, I think I'll go all the way and send these out to be ultrasonically cleaned and the shell cleaned up for painting.


Now, to get the other one out of the boat...

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Got the port HEX out today, cleaned up and ready to get back together.

One issue I found was that the old broken impeller vanes can extrude down the bundle tubes and block them midway through. I found that a Hoppes .22 cleaning rod to be almost the exact diameter and was able to push 4 or 5 vanes from deep in the tubes of each bundle. If unable to remove, you start with a 6%-7% loss of cooling capacity.

Talked to Frank, going to replace thermostats and coolant caps as well as long as I'm this deep into the cooling system. And while I have access, new belts.

I have to quit finding stuff to do "while I'm in there"
 
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carterchapman said:
David - you've sure done a lot! Just think of all the things you will be able to repair during boating season!!!:);)

In the immortal words of Gary (foursons) - "If it ain't broken, you ain't boating"!!! Cracks me up!
Click to expand...

The only thing i want to be fixing in about 6 weeks is an empty cooler...
 
Per franks recommendation, I sent the HEX shells out to be powder coated (primed then color coat for max corrosion prevention). They should be back early this week. Also pulled the expansion tanks per Carter and sanded/ospho'd the rust and repainted.

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Heat Exchanger Shells back from being sandblaster and powder coated. They look very nice!! I think I have finally amassed all belts, hoses, clamps seals, and misc hardware to start reassembling these beasts. Corrosion hopefully kept at bay for a while.

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Now all you have to do is pull your aftercooler covers, powdercoat them and order new CAT Marine Power Decals and you'll be "shinin"!!

The decals were $20 as I recall - my CAT guys at Stowers had them in 2 days...
 
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