ENGINE WATER PUMP
As engine water pumps age,
seals and metal components
can wear, especially in silty
water, and begin to drip. You
can isolate this by placing a
bucket or container under the
water pump, or try observing it
with the engine running. Fixing
it is a case of stripping the
water pump down and
replacing the seals.RUDDER POSTS
Similar in design to a stuffing
box, rudder posts are liable to
leak, especially if they’ve not
been repacked for a while.
Some boats have tubes which
extend to deck level, while
others are sealed at the hull,
but it’s worth checking any
type for leaks and damage
or cracks, especially when
moving the helm across hard
and lock-to-lock. These can
be among the most tricky to
locate as they are usually in
a tight space.DRIPPING STERN GLAND
Another common cause of leaks
is the stern gland. Traditional
stuffing-box glands are designed
to drip at around one drip per
minute, but if you notice a larger
influx of water than usual, this may
be a sign that the compression
nut needs tightening. If this is
ineffective, the gland may require
repacking, or the shaft may be
scored. If a modern ‘dripless’ seal
starts to leak, you have a more
serious problem as the lip seal
may be damaged: or, in other
types, the bellows may have
developed a leak.More serious leaks
With the easy suspects eliminated, you may find
there is still an unexplained leak...HOLES IN THE HULL
Even more unusual than
keel bolt failure, a hole
or crack in the hull is a
possibility nonetheless.
The key is to trace the
water to its source (see
panel) and keep a record
of when the leak seems
worst (eg after sailing on
port tack in particular) to
aid diagnosis.KEELBOLTS Keelbolt leaks are thankfully rare, but it’s worth looking
for telltale signs. Rust around the bolts can be one sign, as can any
cracking or signs of movement. Dry any water found around the bolts
and monitor them carefully. If in any doubt, get the bolts checked out
by a surveyor – drawing one can settle any doubt.Modern stern glands shouldn’t leak, but stuffing boxes are designed to drip
PRACTICAL – tracing leaks
ENGINE HOSES Most diesel engines have a large water pump which
shifts a lot of water around the engine at pressure. A hole in a hose, or
a fractured spigot, can make it look like you’ve developed a hull leak
when in fact it’s the engine, so it’s important to ascertain whether the
leak is still there when the engine isn’t running.Leaks below the waterline
Saltwater leaks are more worrying than freshwater as they imply that the sea is getting in! When searching for
a salty leak, try working out the frequency with which it occurs; for instance, if it only appears when the engine
is running, or perhaps after beating in heavy seas. This will help to identify the cause.
This water pump has been
leaking, as shown by the rustThese screws, which once held a gasket,
had been leaking into Hantu Biru’s hullCOCKPIT DRAIN HOSES
If a significant amount of water
has made its way below, it could
be that a cockpit drain hose has
become holed or detached. If the
water is fresh it’s likely to be the
cockpit end that’s giving trouble.
If salty, it could be the skin fitting
end, but check the cockpit end
too if you’ve been sailing with
green water over the deck.