Dufour Owners Association: new forum reply to Anti Siphon Tube

New reply from Graham Marks

<p>Hi Paul</p>
<p>There is rubber diaphragm installed in the top of the anti siphon tube where the tube is connected, this should be cleaned and inspected annually as part of the engine service, often gets overlooked.</p>
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<p>From the Volvo service manual:</p>
<p>Vacuum valve. Cleaning<br />Some engines have a vacuum valve installed in the<br />seawater piping.<br />WARNING! Risk for water penetration. Close the<br />sea cock.<br />Close the sea cock. Disassemble the valve. Unscrew<br />the hexagonal cover. In the cover there is a membrane<br />and a gasket. Clean all the parts. Turn the<br />cover upside down. Install the membrane first and<br />then the gasket. Turn the valve housing upside down<br />as well. Screw the cover into position, but not too<br />hard (0.2 kpm), or the valve may stop working.<br />Seawater filter. Cleaning<br />The seawater filter is an accessory. Screw off cover<br />(1) and remove seal plate (2). Lift out and clean the<br />insert (3).<br />IMPORTANT! If the boat is used in water that<br />has a lot of contaminants, seaweed etc. the filter<br />must be checked more frequently than indicated<br />in the maintenance schedule. Otherwise there<br />is a risk the filter will clog and the engine will<br />overheat.</p>
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Original Post by Paul Simmons

Anti Siphon Tube

<p>Hi all, whilst trying to trace a leak I found that there is seawater dripping into the engine bilge from what appears to be an overflow tube attached to the top of the seawater anti syphon tube. Is this lube really required? I have taken out, in a yogurt tub, 400ml sea water after one journey and this may well be a factor in the saltwater leak. Anyone had a similar issue? How did you deal with it? Engine is Volvo D2-55c </p>