Mixing Elbow Gasket

[Charlie]

Hi All:

I have had a problem with a water leak in the port rear side of a Yanmar 4JH4E. It rusted a good number of components of my engine including the motor mount, the engine mount that connects the block to the motor mount, the transmission shift handle and a few of the electrical connections in the area. Two years ago I took all the rusted parts off cleaned them so that they are rust free, and repainted them. Well the rust is back. I thought I had done a bad job of cleaning them. Then I realized I had fixed the symptoms but not the problem. What does Gord May have written under his name? I looked for a leak while the engine was running and all seemed fine. A careful inspection of the hoses and they all seem tight. I was able to track the level of the leak b/c it was mostly below the mixing elbow. I decided to take the hoses for the cooling system off. They were all very tight and hard to remove. Finally I took off the exhaust Elbow to inspect it. Three of the four bolts were very tight. I had to use a bit of leverage to get them off. The fourth was difficult to get to -- but it was loose. The rust held it on but I didn't have to "break" the nut free.

I figure this is where my leak is coming from. The exhaust elbow is five years old and looks great inside. The flange that connects to the engine has a bit of surface rust. The gasket is two pieces of metal that have been spot welded together at the top.

I figure I'll buy a new gasket. Given that it is a yanmar it should cost less then a boat buck. But not much. Should I use exhaust sealant? This what I was thinking of using. PERMATEX Permatex® Ultra Copper® Maximum Temperature RTV Silicone Gasket Maker at West Marine If I do should I put the sealant on all four faces of the gasket?



Here are pictures of the parts.
https://picasaweb.google.com/1100267...85902859330306

[Charlie]

Bump this to the top

[delmarrey]

Charlie,

With the pits in the flange (in the picture) I think I would go with some self sealing gasket material. We use these on steam valves for the bonnet gasket. It's graphite on the outside, sandwiching a metal center. It can be cut out with tin snips but the holes do need to be punched. EZ to do with a piece of metal tubing with the edge sharpened.

Mr. Gasket 5960 Ultra Seal Exhaust Gasket : Amazon.com : Automotive

It incorporates a graphite-impregnated facing and a steel expanded metal core that reinforce and increase the tensile strength It is designed and constructed to improve the sealing of exhaust header flanges This gives the gaskets the ability to conform to warped flanges giving them better sealing capabilities without deteriorating or cracking under the excessive heat and pressure that is common in the exhaust system

[Charlie]

Thanks Del that was very helpful. I will look into ordering this stuff. Any thoughts on the sealant?

[delmarrey]

Originally Posted by Charlie

Thanks Del that was very helpful. I will look into ordering this stuff. Any thoughts on the sealant?

You will not need a sealer with this stuff. The graphite seals itself right into the pours/pits. On a valve bonnet we give it a √125 (finish).

[s/v Jedi]

Permatex makes a high temperature gasket dressing (blue stuff, doesn't harden) which works really well together with a new or used gasket. It also helps to keep the gasket in one part when removing it the next time.

[delmarrey]

Originally Posted by s/v Jedi

Permatex makes a high temperature gasket dressing (blue stuff, doesn't harden) which works really well together with a new or used gasket. It also helps to keep the gasket in one part when removing it the next time.

It'll cook. Diesel exhaust runs at about 850º F.

Originally Posted by Permatex® Ultra Blue® Multipurpose RTV Silicone Gasket Maker

OEM specified. Designed specially for high-torque and high vibration applications, like those common in import engines, this premium RTV gasket maker exceeds manufacturers’ performance requirements. Sensorsafe, low odor, and noncorrosive. Maximum vibration resistance, with outstanding resistance to oils, cooling and shop fluids. Guaranteed not to leak. Temperature range -65?F to 500?F (-54°C to 260°C) intermittent.

See more at: Gasket Makers : Permatex® Ultra Blue® Multipurpose RTV Silicone Gasket Maker

Permatex® High-Temp Red RTV Silicone Gasket is a higher temperature range -65?F to 650?F (-54°C to 343°C) intermittent; resists auto and shop fluids.

[s/v Jedi]

Originally Posted by delmarrey

It'll cook. Diesel exhaust runs at about 850º F.

It didn't. Guess I got lucky but will measure temperature of the flange next time I run it and think of it. I think the nearby injection of water cools it down enough at the flange.

[sartorst]

You may want to use a poor mans mill(file) to level the surface by keeping the file on the high spots