Winterizing MD7A

[Pete Zwiefelhofer]

When winterizing my MD7A a quart or 2 of water came out immediately. I ran the engine for 22 minutes and no more water came out (just what looked to be pure antifreeze). Is there a thermostat in the MD7A? Is it possible that water is still in the engine? Is 22 minutes long enough to ensure that I got all the water out? This is not something I can afford to screw-up!! Thanks.



pete@zwiefelhofer.com

[Mike Everett]

Hmmmm. Your question is puzzling. When I winterize my MD7A, the pump sucks up about three or four gallons of fresh water out of a pail, then I add antifreeze, which appears at the exhaust in a matter of seconds. Total running time is a couple of minutes, tops.
There is a thermostat, but it wouldn't shut of the water circulation so completely that water would stop running through.



everett@megalink.net

[Pete Zwiefelhofer]

Mike:

Maybe my question wasn't clear. What I did to winterize the engine was this: I disconnected the raw water intake hose from the seacock and put the open end in a bucket of antifreeze. I disconnected the water exhaust hose from the muffler and put the open end in an empty bucket. Then I started the engine. Once the exhaust discharge changed from water to antifreeze I moved the exhaust hose to the bucket with the antifreeze and raw water intake hose (so I was recycling the same antifreeze through the engine). What surprized and concerned me was how litte water came out of the exhaust hose before it changed to antifreeze and I became concerned that there may still be some water in the engine.

Thanks for your reply.


Pete Zwiefelhofer
7311 W. Burleigh St.
Milwaukee, WI 53210
Phone: (414)445-2590
Fax: (414) 445-2750
email: pete@zwiefelhofer.com



pete@zwiefelhofer.com

[Bob Hiney]

I remove the thermostat before flushing with antifreeze, but am not sure it is necessary. In any event, it's easy to do and can't hurt. Just remember to replace it in the spring!



bob@bestweb.net

[mitch]

You are a nut case!

Mike:

Maybe my question wasn't clear. What I did to winterize the engine was this: I disconnected the raw water intake hose from the seacock and put the open end in a bucket of antifreeze. I disconnected the water exhaust hose from the muffler and put the open end in an empty bucket. Then I started the engine. Once the exhaust discharge changed from water to antifreeze I moved the exhaust hose to the bucket with the antifreeze and raw water intake hose (so I was recycling the same antifreeze through the engine). What surprized and concerned me was how litte water came out of the exhaust hose before it changed to antifreeze and I became concerned that there may still be some water in the engine.

Thanks for your reply.


Pete Zwiefelhofer
7311 W. Burleigh St.
Milwaukee, WI 53210
Phone: (414)445-2590
Fax: (414) 445-2750
email: pete@zwiefelhofer.com

[Mike Everett]

Well, I don't think you're a nut case!
Having winterized my MD7A a couple of days ago, I can now see why your procedure seemed to take more time than I thought it should.
Last year, when I winterized for the first time, I ran the fresh water and then antifreeze through the system after I had run the engine for an hour or so.
This year, I did the same procedure with a cold engine. It took four or five times longer for the fresh water to pass through the cooling system.
The difference from year to year, of course, is that the thermostat was doing its job.
I do think that once you see antifreeze in the exhaust then further flushing is redundant.



everett@megalink.net

[Pete Zwiefelhofer]

Mike:

My engine was cold when I was winterizing it.

Pete



pete@zwiefelhofer.com