Question for all you freshwater cooled dudes.
When you winterize your engines, do you leave the drain plug out of the heat exchangers or do you drain them, then re install the drain plug?
Where I live it's been unusually cold for this time of the year. I was worried that they might be half frozen and wanted to make sure they are fully drained before I re installed the plug but then thought, why just not leave them out?
The service manual calls for you to re install them. I can't see any harm in leaving them out.
Thoughts?
Howdy,
I have "winterized my (FULL) closed cooling 7.4L by using a 5 gallon bucket filled with (slightly "richer" than) 50/50 AF & water sitting (initially) on the swim step.
I use a hose long enough so I can fill it (the hose) with the mix and start a siphon....... At the flush adapter end, I have a ball valve inline so I can open it right before my helper starts the engine (idle) (no bubbles in the hose )
Raw water pumps (especially engine mounted Bravo/Volvo) usually won't draw water up into the them without a little "head pressure" to start the suction..
Assuming you do not have thru-hull exhaust (that will have some water coming out) You can capture pretty much all of the mix coming out of the exhaust in the prop-center. With mine, I place a container (like a cat-box ) under the drive and catch it all once it starts coming out of the drive (with the exhaust)
If you're quick, right before 5-gallon bucket drains, you can hold the suction end of the hose at the bottom, set it on the ground near the drive where you have the "cat-box) and quickly transfer the suction end of the hose to the "cat box" and you'll suction the mix right where it's draining out.
It should be full enough by then to keep the suction end covered and you won't draw much air into the system. Doing this will run 50/50(or more) AF mix all through the raw water side of your cooling system.
If you set up a big enough "Cat-Box" for collection, you can collect and reuse the same coolant every year minus whatever is left pooled inside the HE, hoses or risers etc....
ANYONE reading this with OPEN cooling, DO NOT DO THIS!!!
I have also tried draining the HE but I never leave the drain plug out (bad juju) I would just forget to put it back in and wonder why my bilge pump is running!!
The other point that should probably be drained (if you're just draining) is the hose from the raw water pump on a Bravo that goes under the engine to the power steering cooler on the engine port side. I was just disconnecting it to drain it and immediately re-connecting it.
I never really got very much out of the HE when I did drain ........Now since my boat always resides in an insulated garage that never gets below about 40 degrees or so, I haven't drained anything for about 10 years.
ymmv
Cheers,
Rick
