heat exchanger.

[wyndham]

So I went down to the boat an Saturday morning with the youngest son, read the Yanmar book, looked at the pictures and tried to pull the heat exchanger to clean it.
Book says remove side plates, O-rings and gaskets, slide cooling tube assembly out of manifold.
Took off the side plates, pulled the O-rings. Nothing slides nowhere, no how nothing. Sixteenth of inch forawrd and back at the most.
Sounds and feels like it's hitting something mechanical. I was tempted to give it a shot or two with the amllet but kept my cool.
The book shows nothing. The book says nothing about anyhting holding the cooling tube assembly in place. The Yamnar website has very pretty pictures but useless.
The local yard will not put a mechanic on the phone.
Ideas? Thoughts?
Thanks in advance.....

[Scott Rosen]

Might there be a pencil zinc in the way? If so, it should be easy to spot and remove.

[Gary E]

I too would look for a pencil zinc but they are usually in the end cap not sticking in through the shell, I think. So, look on the outside of the shell for anything that looks like you can put a wrench on it, that may be holding it in place.

Reminds me of a story...
I was a kid and chipped a tooth in the manual transmission of the car. No big deal, buy the gear fronm the trans shop and put it together myself. Got the trans out from under the car easy and started unbolting things, tug here...umm.. that's as far as that's gona go cuz that gear is bigger than the hole I think it ougt to fit thru... ok..same procedure at the other end....resulted in the same thing with the addition of a lot of ball bearings falling out...

OPPPPPPPPS ,,,now whut...

I took a WALK up to said trans shop and asked a few questions....he was very helpfull, said.."You didnt remove that internal tru arc snap ring?" ...uhhh, what snap ring... ahh...you'l never get it apart without the special tool ...

Ok... long story I took all the parts to him in a bushell basket and he fixed it...

Remids me of Terry Bradshaw setting that trans on the Cottman guys counter...

[wyndham]

No zinc in the way. I checked that. Zincs are nearby but parralele with the core and the tube assembly. The parts guy at the marina blew up the computer image of the page from the manual and we identified every single part that goes in the manifold. As far as he and I could tell there is nothing holding the cooling tube bundle in the core.
I did manage to talk to a mechanic today and said to take a block of wood and give it a good shot with a mallet. he says there is nothing mechanical in there just scale and rust and crap.
I must admit I am a little nervous but I will try it. I may put the side plates back on and fill the whole thing with Lime Away first and see if that softens up whatever it is that is holding it in. The discharge side plate was much more rused and scaley than the intake end, no surprise there, and the gasket at the discharge end was compltely shot.
If I can get down there befor Saturday morning I'll let you know.
Any other thoughts in the meantime are surely welcome.

[Gerald]

I have removed a couple tubes you are talking about. Both slid out without much trouble. It is just a machined tube that slides into the machined cast iron housing. My preference would be to support the cast iron housing and push the bronze tube out with a jack. I broke the hose nipple off the other day trying to take it out. The cast iron was of poor quality or reduced in strength because of salt water?
Gerald

[wyndham]

The exhaust manifold is cast iron. The "Cooling Tube" as the book calls it appears to be aluminum. The "Bundle" of smaller tubes sits inside the cooling tube. According to the book the cooling tube and the bundle can "Slid" out once the side plates ae removed. The bundle will move about about a 1/16" in either direction but thats all. I assume once the bundle is removed the cooling tube can then be pushed out of the block.
There is little or no room for a jack although slow steady pressure makes more sense to me than simply pounding on it with a mallet and a block of wood as had been suggested.
I am always wary the first time I pull something out or take something apart unless I already put ti together. I have gone cover to cover through the Yanmar book and studied the drawing of the assembly but I just can't help feeling that I'm missing something. It just feels like something mechanical is holding this thing in place rather than scale and rust. Friday afternoon will be the moment of truth.......wish me luck.

[Gerald]

With the latest post you can probably forget everything that I advised. My heat exchangers are in the front of the motor and both motors have cast iron heat exchangers. One motor had a cast iron pipe from the exhaust manifold and the other aluminum. The cast iron one rusted out and had a hole about 4" X 2". For that I bought a sail boat real cheap. The internal part of the heat exchangers on my motors are bronze tubes about 4" in diameter and are soldered together so that you may not remove the several 1/4" tubes that have the sea water running thru them. That entire assembly pushes out one end or the other with no real problem. The zinc is in one of the end caps.
Added ..........On my heat exchanger I would place the cast iron part on two parallel blocks of wood, place a block of wood less than 4" diameter above on the 4" bronze tube and a jack on top of that to push the bronze tube out the bottom.
Gerald

[ 06-08-2005, 07:11 PM: Message edited by: Gerald ]

[William R Roche]

Try the Yanmar forum, http://www.freeboards.net/?mforum=yanmarhelp or access from http://www.yanmarhelp.com/
Dave is an experienced engineer and very helpful.

[wyndham]

Thanks for the info, I just e-mailed them.

[wyndham]

The yanmar people got back to me this morning, early, just use a wood block and pound the cooling tube bundle out of the cooling tube.
Friday afternoon I replaced the side plates with new gaskets, loosened the intake and ischarge hoses and pointed them both skyward and filled the whole heat exchager with Lime Away. I ti fizzed and bubbled and over flowed. I did it again and just let it all sit for an hour os so while I monkeyed around with the jib furler, got the main squared away and all the other odd jobs I could think of. Reconnected the hoses, started the engine and VOILA! About a ton of crap came out the exhaust. Lots of good water discharge, no steam in the exhaust. Seems everything is back in good working order and the heat exchanger is clean. I guess I'll mkae this a routine maintenance procedure from now on.
One thing id id notice was how many of the hose clamps on the engine were rusty. Went to the hardware store and bougth a big hanful of various sizes, some for the tool box and some for the more crroded ones. Gave 'em all a shot of wd-40, put the cover back on and went sailing yesterday for the first time this season.
I feel much better now.
Thanks for all the advice and help.