Beta stack tube O-rings are not sealing - re-build the heat exchanger - 1 - 2018

Well it is not like I have not done this before. 

I have also blogged about this O ring replacement . 

This time however I was not able to get the O rings to seal on the 38 Beta Marine engine heat exchanger.. It appears this could be at the rear of the heat exchanger. I tried installing the stack tube about a half dozen times but it still persisted in leaking. I tried old and new O rings. Tried sanding the exhaust manifold with #400 sandpaper and it seemed smooth enough for the O rings to seal?

 Here you can see the deteriorated zinc inside the stern 
stack tube end cap, it has deteriorated. 

Stern end cap cleaned up a bit.

 I put new bolt washer\O rings on. 

 

The stack tube showing some clogged tubes.

 The forward end.

 I used a wooden skewer.

 Cleaning the stack tube.

 Cleaning up the radiator cap.

Stant 12270 30 Pound Cooling System And Pressure Cap Tester

Putting on testing cap.

Testing with the Stant 12270 30 Pound Cooling System And Pressure Cap Tester

 

 So we got a mechanic through Jorge at SYS in Paradise Village Marina. His name is Luis.

Luis the mechanic tried to seal the stack tube and was not successful. He tried again in a day or so with oversized O rings. That did not work either.

As you can see he has removed the 2" exhaust hose.

After 6 1\2 years the 2" exhaust hose.is showing signs of wear

 with some rust on top and by the bottom around the flange. 

We decided that if we must remove the heat exchanger then we should replace this hose and see if the exhaust elbow needs any attention.

This is the port aft side of the Beta Marine engine.

The big problem is that Phil, who installed the Beta Marine engine, had the motor mounts made and this one is in the way of sliding out the heat exchanger. It is in the way of removing the heat exchanger.😡 So Luis is working out a plan as I write this.

The heat exchanger will go to the fabrication\weld shop where they will weld some metal into the area where it is leaking and then machine it to spec. It will hopefully be easier and less expensive then trying to get a heat exchange into Puerto Vallarta, Mexico. 

As for any gaskets, that we do not know yet?

I asked Luis to also replace the 5\8 heater hose that goes from the bottom of the heat exchanger to the new valve we installed on the port side. That hose is a bit short and I would like the valve up higher. Anyway, now would be the time to do it as again the motor mount is in the way of getting at that hose. It can be done but it is hard. So there will be more posting on this.