boat owner

Cleaning the water pump

1

Once the pump is separated
from its bracket it is ready for
servicing, which begins with removal
of the cover plate. With the screws
removed, a light tap will usually
suffi ce to free off the cover plate.

2

With the cover off, the amount

of wear on the inside of the

cover face can be checked. Where

there is excessive wear these covers

can often be fi tted inside out.

3

Removing the impeller is generally

an easy job if you use a proper puller.

This is the latest Jabsco Compact puller.

If you use screwdriver blades to wrench out the

impeller you will defi nitely damage the impeller and probably

also the edges of the pump body, which may prevent the

cover from sealing properly when reassembled.

4

In normal

circumstances, once

the impeller is removed it

is checked for damage

and wear and then either

refi tted or replaced. Splits

like this indicate an impeller

close to failure.

5

Due to the layout of the engine and

the impossibility of servicing the

pump while in place I carry a complete

spare pump on board ready for a quick

changeover. In this case it will replace

the old pump, which will become the

spare once serviced.

6

Once the pipework and pulley

are removed from the old

pump the new one can be

assembled in a few minutes,

starting by installing the hose tails

into the pump using plumbers’

PTFE tape to seal the threads.

7

The pulley is fi tted next. This must
be lined up with the engine crankshaft
pulley once the pump is in position, so it
is left loosely fi tted at this stage.

8

The pump is refi tted and the hoses connected. The pulley is lined up with the crankshaft

pulley and the securing Allen screw tightened. The drive belts can then be renewed. When

fi tting a new belt it is sometimes a little on the short side, and the trick to getting it onto the pulleys

is to place it round the crankshaft pulley and then push it as far onto the alternator (or pump) pulley

as possible. Then, while holding the belt in position, turn the engine over with a spanner on the

crankshaft pulley nut and the belt will roll into place. It can then be tensioned in the normal manner.

TOP TIP

It is not good practice

to use right-angled elbows on

water systems as they restrict

the free fl ow of water. Sweeping

bends give the best fl

ow, but

if there is no alternative in a

tight installation then they will

do the job – and in this case

they have not caused any

overheating problems!

PRACTICAL