[MC1600]

The mufflers in my 4000 have no drains. I find it kind of wasteful to push 30gals of antifreeze through each engine for what should take 5. If I pull the inlet hose, will the mufflers drain enough to prevent having to fill them with antifreeze?

[August Rush]

The mufflers in my 4000 have no drains. I find it kind of wasteful to push 30gals of antifreeze through each engine for what should take 5. If I pull the inlet hose, will the mufflers drain enough to prevent having to fill them with antifreeze?

I have the same boat and have the same concerns about pushing 15 gallons each through the exhaust.   How would removing an inlet hose help drain them?  I think you mean remove exhaust hose?  If so, good luck reaching it...lol 

The amount of antifreeze is probably overkill.  I assume there is lots of room for expansion but it looks like it would be a nightmare to have to replace one of those mufflers so I will just keeping using antifreeze.

[giff1]

I just bought a 3500 express and also concerned about the amount of antifreeze to use. I'm planning on using 8 gallons per engine.
I hope more members chime in with their experience.

[MC1600]

Thanks August. Guess the safe/smartest bet is to just keep biting the bullet and paying for the antifreeze.

[Lobsta]

I don't understand the post. Why are you wanting to fill the muffler with anti freeze? When i winterize we run the engine and start pouring AF in until we get pink out the exhaust. That is usually about 6 gallons in our case. Am i not understanding something?

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Cummins 5.9's in our 3200

[MC1600]

Our boats have massive mufflers that hold a lot of water. I think I used about 20gal/engine last year before getting pure antifreeze out the back.