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Changing antifreeze

I have a Beta 43 with keel cooling and calorifier circuit. I want to change the antifreeze and would like to know the best way of doing it. I would like to flush the system through once drained before refilling with fresh antifreeze mix. Do I need to remove the hoses for the skin tank and the calorifier from the engine in order to flush with fresh water or can I flush without doing that? Many thanks

Asked by: Raymond Fowler  | 7.48am, Thursday 5 July


WW says:

It is an excellent idea to flush the cooling system. If you are lucky enough to have a drain tap at the lowest point that makes it easier to drain the antifreeze solution from the system; otherwise the bottom hose will need to be removed. Let the air in by taking the cap off.
Most of the sludge will have collected in the skin tank but there could also be some in the calorifier circuit. To give every part of the system a thorough flush it would be easier to divide it up; the engine, the calorifier and the skin tank(s). Disconnecting the hoses will facilitate the job.

Rupert Smedley  | 1.40PM, Thursday 5 July

Once you have done the disconnection, it may be worth adding a fitting with a t-piece in, to which you can fit a tap to a hose connection (and prefereably be able to cap the fitting)- on the lowest hose to the skin tank outlet. This means that in future you can easily drain the coolant by using a hand pump, rather than letting it flood into the bilge. remember that most antifreeze solutions are dangerous for the environment and should not just be pumped overboard, but collected to discharge in a proper waste facility ashore.

Mark Langley  | 1.33PM, Friday 6 July

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