8.1L 496 MAG - Air Actuated Single Point Drain Winterization

Squatch68

Hello again folks

Update - After more research I better understand the system now.  Its not actually pressurizing the raw water system, its only pressurizing actuators that open drain valves.  I must have an airline that has come loose or a failed actuator.  I will trace those lines out tomorrow.  I think its best to just open the blue drain plus anyways, let the water drain out, then run anti-freeze through the system. 

Original - I went to drain the raw water side of my 496 MAG using the single point drain/bicycle pump pressurization method.  Followed the manual step by step.  I could not get the system to pressurize so that the two green indicators would pop out.  Pretty sure I could hear the air exhausting out of somewhere near the transom with every stroke of the pump.  Thinking about the cooling circuit, I'm not sure how the system could ever be pressurized as its drawing water from the sterndrive and exhausting water out the exhaust?  Am I missing something here?  

Its probably not super important, I am going to be running antifreeze through the system anyways, and can just open all the blue drain points before hand.  But I would really like to understand why the pumping method isn't working for me. 

Freshwater boat.  No seacock and inlet water valve as cooling water is drawn from the sterndrive. 

Thanks in advance! 

Jim 

earl1z19

I think draining with the removable plugs is probably best. 

davidbrooks

i actually took my blue air pumps and just put them in a drawer down below.  I never used them and it was just one less thing to worry about dropping in the bilge.

reneechris14

To my belief the the single point drain is not the best way to winterize,  it would be more of a design for someone that would leave the boat in the water on cold nights. Pump it up to drain manifolds, come back release pressure and go for a ride. I would run plenty of pink stuff then pull the blue plugs for winter.

Liberty44140

Agree with Chris, on the 342 I would use this to drain the system before winterizing only because I had it and it’s one of those things that won’t work unless it’s used so that way once a year it got used. But yea not needed unless you are boating somewhere that rarely gets cold and you just blow it out in the winter to be sure. 

Dream_Inn

Just note, agreeing with Liberty, the valve on the bottom of seawater pump (that opens when you use the pump) can get stuck open sometimes.  This is actually because it does not get used but maybe once a year.

LaRea

Good idea, bad implementation.  The fittings are too fragile, and the tubing is wimpy plastic that is not properly routed and supported.  It's a 2-year solution for a 20-year engine.  

It didn't work when I bought my current boat eight years ago, and I don't miss it.