lazy heads

[samwise]

Our Sadler 29 has one of the early Par Brydon heads, which served us well until the end of last season when the piston end corroded and dropped off. The unit is now obsolescent, but you can still get repair kits for them. Over the winter lay up I dismantled the whole unit, cleaned it up and replaced every valve ( except the very difficult one right in the top of the piston unit).

It blows out ok but won't suck in flush water unless it is primed by putting water in the bowl. It seems to work ok if you leave the inlet seacock open all the time. But if you close it ( my discipline has always been to close off both seacocks after every visit) then you get no flush next time unless you prime.

Any ideas?

A whole new unit is less that £100 and come the day when spares are no longer available, I'll have to take the plunge, but I guess I'm on a point of principle in trying to keep the thing going.

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[Avocet]

Mine's doing that too. It's not the same make as your but I'm pretty certain mine is due to my having anti-fouled over too many of the holes in the inlet strainer and is nothing to do wit hthe pump unit as such. Alternatively, you could have a small air leak interneally. Take it to bits and check that all the rubber gaskets and flap valves are sitting correctly on their seats. Maybe worth adding a smear of silicone grease to the mating faces before reassembly.


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[pvb]

The very difficult one...

...isn't that difficult to check or replace. It's just a screwdriver job. The valves in the body at the top of the piston are the important ones - well worth a look.

Incidentally, putting water in the bowl shouldn't in any way affect the prime of the intake pump system.

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