Mercruiser 5.0 MPI w/Bravo III - drain system

[dvan1901]

Looking to get some feedback from those with a Mercruiser 5.0 MPI with a Bravo III that have the 3 point engine drain system. What I'm wondering is, have you used that 3 point system to drain your engine and did it make it through the winter ok? I drained mine yesterday and all seemed fine and looking at the diagrams in the manual of the system it looks like it really does get all the water out as everything drains downward into these 3 drain points.

 

[HT32BSX115]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

You're probably ok using the 3 point system.

If your boat is more than a year or 2 old you really should remove the valves once in a while and poke a piece of wire in the holes to clear out any rust flakes in there.

If you don't do that the rust and sand that invariably collects there can plug up the holes enough to make it appear that it's completely drained while trapping water that will subsequently freeze and possibly break the engine/manifolds etc.


You want to ENSURE that you have drained ALL of the water from the block and manifolds. As a famous Volvo expert once said......AIR DOESN'T FREEZE! (at least at the temps that one experiences on this planet!)


Cheers,


Rick

 

[dvan1901]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

My engine is only a month old, been run four days so rust shouldn't be a problem, maybe just some sediment, but the water that came out (about a gallon or so) was clear of any debris. Both manifolds have a hose on the bottom that drain into these collection points and there is also a hose that comes out of each side of the engine and into these points. It seems to be a well designed system, all flowing down with minimal to no turns and mainly 1/2-3/4" hose. I do plan to have it winterized by the mechanic that is onsite at my storage place; mainly because the engine is new (less than 10 hours on it) and just want them to look it over completely.

 

[Don S]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

As long as there isn't any sand or mud or (sediment) plugging the holes going to the drain hoses, you will be fine. Of course, that is impossible to verify without removing the hoses and disassembling the drain system just to check.

 

[dvan1901]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

As long as there isn't any sand or mud or (sediment) plugging the holes going to the drain hoses, you will be fine. Of course, that is impossible to verify without removing the hoses and disassembling the drain system just to check.

One of the good things about the system is that below each manifold is the tube that connects into the drain system; I can pull that off at the manifold and see if anything else comes out and poke around. Same goes for the engine block. I could also pour some water down the hoses and make sure a good clean flow comes out the drain system. Sounds like a plan...

 

[HT32BSX115]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

I eliminated the problem by putting antifreeze in the engine........permanently!

 

[thrasher]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

Permanently might be an overstatement!! Radiators/heat exchangers do corrode and leak!! Eventually...

 

[HT32BSX115]

Re: Mercruiser 5.0 MPI w/Bravo III - drain system

I use the word loosely!