Winterizing Seawater Cooling system

[Bob Carlton]

The manual for my diesel inboard (Universal 18hp in 1994 MKII 28') advises winterization of the seawater cooling side as follows:1. drain hoses and pump;2. close the through-hull where the water comes in and disconnect hose at raw water inlet;3. run antifreeze from the raw water inlet hose, through the system until it exits.The through-hull through which the raw water/ antifreeze will exit is difficult to access from outside the boat(above the water line but under the port aft hull). Does any one have any tips on how to capture the discharge? The discharge hose inside the boat is also difficult to access both at the engine and at the discharge through-hull. Thanks in advance.

 

[Walt]

Winterizing

Your instructions are pretty much correct. Just forget about trying to drain the hoses and pump. It's not necessary if you pump enough antifreeze thru. So regardless of whether the boat is in or out of the water do this: 1. shut off thru hull; 2. disconnect intake hose from thru hull; 3. if the intake hose is not long enough to reach into a bucket, attach another section of the same size hose to extend the hose reach to a bucket; 4. fill the bucket with 3 gallons of non-toxic (pink) antifreeze; 5. fill the hose with some of the antifreeze (to prime the pump) and then plunge the end of the hose into the bucket; 6. have a helper start the engine and watch for pink discharge from exhaust port. Don't worry about catching it, it's not toxic; 7. call to the helper to shut off engine when the bucket is almost empty; 8. reconnect the hose and you're done. (unless the boat will stay in the water, then you'll want to ge some antifreeze into that thru hull. Use your wife's turkey baster - Thanksgiving is over!)