Anyone ever have a Tides dripless shaft log melt?

[rondds]

Got back in from a 2 1/2 hour run, opened the hatch to find water in the bilge sumps. Checked the dripless and the stbd was leaking a healthy stream and the shaft was too hot to touch.

Had the boat hauled and autopsy reveals that the entire plastic housing that slides inside the blue hose tube had melted from the heat, presumably from a lack of cooling water. I called Tides and they confirmed that is likely what had happened. The tech stated that they like to see 1g per minute at idle. I started the boat on land and ran it from a bucket and was getting less than 1/2 gallon per minute.

On my engines, the feed for the dripless water comes off the end of the exhaust manifold.

Has this happened to anyone else and if so what was the cause of the loss of cooling water? I might add that the boat ran fine during that entire trip, with both engines running at the similar temps. I have no idea when exactly the melting occurred - could have been minute one, or minute 125. But I do know that before that run, the engine room check revealed zero water and all was normal. The seal was not leaking prior to this event.

 

[sdleo26]

Did you have a crossover from opposite side (other motor) ? I had one get blocked from mineral deposits which stopped the water from flowing via exhaust manifold fitting. Luckily I had the tee from the other motor supplying water. If it happened on the opposite side I would of burnt up both sides. I ran all season like that as I did not find it until I was commissioning boat for the following season on the hard. Good luck, at least you are an expert on how to take the shafts out.

 

[rondds]

This was the old Tides Strong Seal, so only one nipple - I set up a cross over as per Tides' instructions (by putting a T in the line) but that didn't work I guess.

Expert? LOL. Not sure about that, but I have an understanding of how it works - just need to figure out why, in this case, it DIDN'T work!

 

[Jimmy Buoy]

Had it happen 8yrs ago on mine. Cooling lines were full of little sea creatures (salt water boat) which along with corroded aluminum inside the manifold resulted in blocked off the water supply. No cooling water = melted housing. That reminds me... I was going to check the water flow annually but never have - better do that even though I'm now in fresh water!

 

[cfd95]

Hose was probably clogged with rust and scale from the manifold.
My cooling hoses for the seals have a tee in the water hose of the heat exchanger.

 

[Fred]

My boat has the factory cross over and the new style seals. I have noted while flushing each engine before wintering, with the boat blocked, that the seal on the side of the running engine flows much more volume of water than the other seal. I believe this is normal and expected.
I believe the purpose of the crossover is to allow you to limp home on one engine without causing damage to the free wheeling shaft seal. In the case of blockage while at cruising speed I suspect there would be a real possibility of overheating on the blocked side.

 

[rondds]

Boat goes back in the water on Friday. Plan is to remove the hose and the fitting from the exhaust manifold with the boat in the water (guess I'm going to have to plug that hose up) to ck for obstructions. Then replace the fitting and hose and check flow volume. Will do this on both engines.

 

[rondds]

Got back in the water today. No leaks. I idled over to the slip and immediately started looking into the water flow issue. I took the hose off the fitting, put on a short length of hose and ran it to a bucket and started the engine. A trickle at best. No where near 1 gallon per minute that Tides recommends. Removed the brass elbow that exits the manifold and, under running water, chipped at it with a piece of wire. You wouldn't believe the gunk in there. Got it all cleaned out, then poked into the manifold with the wire and used a shop vac to get out whatever was going on in there. Put the fitting back on and my short length of hose and this is what a gallon per minute looks like...

[video]http://vid250.photobucket.com/albums/gg252/rlumachi/Boat%20Maintenance%20Pix/Dripless/20160722_115010_zpsm5wkcfgs.mp4[/video]

That was on the engine that did NOT fry the dripless. Now over to the one that did. Same procedure revealed the same results. So therein lay the problem. Couple of observations/take home messages...

1. we should all be checking this periodically. Tides recommends annually.
2. pulling the water supply off the exhaust manifold is stupid. Maybe there's a reason, but the water is considerably hotter in the manifold and manifolds are notorious for getting flakey and rusty. Why not from an oil cooler, or a T in the line somewhere else (like the water feed to the cool fuel module)?
3. after the above procedures, I also checked each hose (that leads from the manifold to the dripless) for gunk. Blew it out (shop-vac in reverse). Going to replace the stbd hose b/c some dumbass put a brass coupler to make the hose longer. This creates more points for failure (hose clamps) and the fitting is another has a narrower diameter than the hose and as such creates another point where debris can get lodged.
4. I plan to change the elbow that leaves the manifold to a straight fitting. One less turn, one less bit of resistance to flow, and one less point for debris to accumulate.

 

[HUMPH]

Great idea Ron. I need to pull my hoses and check for flow as well. May as well give the seals plenty of water to help them last as long as possible! I'm glad it was a pretty simple fix.

 

[Fred]

Thanks Ron for that info.
I also found the brass fittings to be partially blocked with a white hard material when I changed manifolds two years ago.
This is something that must be monitored.

 

[cfd95]

Ron
Tides sells the Tee and hose kits.
Why don't you tap off the raw water hose off the heat exchanger.
My boat came from Sea Ray with this configuration.
You don't have to worry as much about stuff clogging the fitting.
I replaced both of my seal assemblies this year. Sea Ray used 3/8 fuel line for the feed hoses.
I replaced with blue silicone hose. Both were pumping out good water flow when i ran on land.

 

[rondds]

Cfd5....thanks not a bad idea at all!

 

[rondds]

After putting everything back together, I went back a week later to replace the brass elbow with a straight brass fitting. When I took off the elbow there was more crap/rust partially obstructing the new fitting. So I decided to check into the info cfd95 mentioned above. Tapping off a crusty manifold for cooling water just doesn't seem to be the best idea. So I contacted Tides and they do sell a kit that contains all the stuff you see below for $27.00. The brass fitting is 1" (the diameter of the hose I planned to tap into), but the come in all different sizes.

This looked like a good place to tap into. Less subject to crud accumulation...

Cut in...

Removed this straight fitting (which I put in a week ago) to find this chunk inside...

Insert brass plug into manifold where fitting used to be...

Installation complete...

I did not use the silicone hose provided by Tides b/c it was almost 100* today and the hose to the dripless is new (installed about 2 weeks ago). Spent $70 on that stupid hose alone so, dammit, I'm going to use it. Thought the blue hose is definitely cooler looking. Maybe I'll swap it in the fall, when the boat is on land. To do both engines took about 45 minutes, but I have very good access in this boat (one reason for picking it when shopping!)

Now, it is clear to me that my manifolds may be shedding a bit more metal than I'd like them to, so I'm going to have to plan on replacing them. This is the 7th season since the repower and the manifolds are original, with about 300 hours on them - 3 years on the Long Island Sound, 4 in the brackish waters of the Metedeconk River. The engines run btwn 165 and 171* (data from the ECM) and I shot readings all around with an IR temp gun and they are all within normal limits. So there doesn't seem to be any imminent danger, but it's getting to be about that time. Not a cheap endeavor but I guess it's just regular maintenance.

 

[cfd95]

Nice job.
That's the exact same way mine are plumbed in.
I see your risers are dry joint style.
Is there any advantage for using them on a FWC motor.
Im going to replace mine after this season and was wondering which ones to use (conventional or dry joint).

 

[rondds]

Thanks...
And thanks for the tip!!

That is how Merc designed the 8.1 - dry joint with manifolds that are raw water cooled. Only the block is FWC. With the previous big block full closed-cooling system (7.4/454) the elbows were raw water cooled and the manifolds were fresh. Supposedly the 8.1 design is better b/c the main point of failure in the 7.4 was the gasket btwn the elbow and the manifold. It does mean that the 8.1 manifolds (in salt water applications) won't last as long. You'd think they'd be cheaper to buy since they'll need more frequent replacement but they're about 2.5x the cost of the 7.4 manifolds.

I don't know too much about your 350s but I don't think you have a choice of changing the design - you pretty much have to put back what's there. Other's may know better.

 

[Sea Ray Mark]

Ron, my past two 37 Sea Ray's with 380hp Horizons had the tee fitting plumbed in exactly were you just did yours. Can't image why they would have changed it to the set up you had other then to save on the cost of the tee fitting. Not sure how my 33 is plumbed but I'm going to check on it the next time I feel like doing a head stand. It would be interesting to talk to the people who comes up with these designs to try to understand what they were thinking. Seems crazy

 

[RAW BAR]

Old thread but damn good one! Worth bumping.

I had the same failure end of last summer and replaced the seal with the help of a great guy who had to take a ferry out multiple times to help. I want to move the tap to somewhere before the manifold like you did. Is yours right after the seawater pump? Any concern with tapping a little of the cold water before it gets to your heat exchanger where it's needed most?

 

[techmitch]

Old thread but damn good one! Worth bumping.

I had the same failure end of last summer and replaced the seal with the help of a great guy who had to take a ferry out multiple times to help. I want to move the tap to somewhere before the manifold like you did. Is yours right after the seawater pump? Any concern with tapping a little of the cold water before it gets to your heat exchanger where it's needed most?

Interesting thought. Where are you located? You should complete your profile with this info. so others can better assess these and any other questions you may have.

 

[RAW BAR]

Interesting thought. Where are you located? You should complete your profile with this info. so others can better assess these and any other questions you may have.

RI, cool salt water

 

[techmitch]

Sorry I didn't do my homework.
Claiborne Pell/Newport