Leaking anti siphon bend

[fliti]

My anti siphon bend in the raw water input for the engine has begun to leak. It's fitted with a tube from the valve head that drains into the engine pan and drips with increasing intensity as I increase revs beyond about 1800. Collects perhaps a half cup of water every hour. I have opened it up and poured in some vinegar to dissolve any accumulated salt crystals but it's still weeping. Is this something I should worry about?

 

[pvb]

What sort is it? If it's the metal Volvo Penta type, they are prone to leaking.

 

[fliti]

What sort is it? If it's the metal Volvo Penta type, they are prone to leaking.

it's a plastic one supplied originally by Yanmar.

 

[VicS]

My anti siphon bend in the raw water input for the engine has begun to leak. It's fitted with a tube from the valve head that drains into the engine pan and drips with increasing intensity as I increase revs beyond about 1800. Collects perhaps a half cup of water every hour. I have opened it up and poured in some vinegar to dissolve any accumulated salt crystals but it's still weeping. Is this something I should worry about?

No problem until it becomes nuisance........ at least while its dribbling it shows it's not blocked!

but 1/2 cup an hour in my book would be a nuisance although a small dribble can be collected in a bottle and emptied out periodically

Don't lead the tube lower than the water level though or it could form a siphon on its own and prevent the valve breaking the siphon in the cooling system.

Time to consider properly overhauling the valve perhaps or removing its innards altogether and converting it to one that discharges a continuous pee stream overboard or visibly into a cockpit drain.

 

[macd]

Fliti: I'm assuming from your description that it's the type with a one-way valve, rather than the piddle-type? If so, it looks like you need to disassemble the valve, if possible, to check it out. It may be that you can convert it to a piddler if you wish, which isn't so prone to salt encrustation problems, (although you'd have to plumb the piddle tube to somewhere convenient, such as a cockpit drain).

Incidentally it's more usual to have the anti-syphon between engine and exhaust elbow, rather than "in the raw water input".

 

[pvb]

Incidentally it's more usual to have the anti-syphon between engine and exhaust elbow, rather than "in the raw water input".

I think it already is, otherwise the dribble wouldn't increase with engine revs.

 

[VicS]

Incidentally it's more usual to have the anti-syphon between engine and exhaust elbow, rather than "in the raw water input".

True but either place is acceptable and with some engines in the pump delivery pipework is the only possible place.

Just so long as its not on the suction side of the pump!

 

[Max K]

What sort is it? If it's the metal Volvo Penta type, they are prone to leaking.

Mine is connected by a rubber tube to a purpose made inlet into the exhaust muffler. This was done by the Volvo agents as before this, the hot salt water made a dreadful mess of the back of the engine.

 

[VicS]

I think it already is, otherwise the dribble wouldn't increase with engine revs.

Yes it would ... if in the pump delivery pipe work.

 

[pvb]

Yes it would ... if in the pump delivery pipe work.

Hair-splitting, my response was to macd's comment "rather than "in the raw water input".

 

[VicS]

Hair-splitting, my response was to macd's comment "rather than "in the raw water input".

I read that as meaning pump delivery because if on the suction side of the pump it suck in air and cause general cooling problems due to lack of water flow.

 

[prv]

Incidentally it's more usual to have the anti-syphon between engine and exhaust elbow, rather than "in the raw water input".

Anywhere after the pump is fine. It's been directly after the pump in both our boats; between heat exchanger and exhaust would not be possible on the current one.

Pete

 

[peteK]

My anti siphon bend in the raw water input for the engine has begun to leak. It's fitted with a tube from the valve head that drains into the engine pan and drips with increasing intensity as I increase revs beyond about 1800. Collects perhaps a half cup of water every hour. I have opened it up and poured in some vinegar to dissolve any accumulated salt crystals but it's still weeping. Is this something I should worry about?

May be a sign that there is a partial blockage perhaps in the heat exchanger or exhaust elbow