That's it, the nice days are here. We put our boat back in the water. Well winterized, the engine starts again without concern. But surprise, by throwing an eye on the exhaust we realize that the engine does not spit water as usual. Is there a problem with the water pump? Don't worry, it's probably the pump wheel that didn't stand the winter. A small dismantling and replacement is necessary. Step by step in pictures.
First of all, before any operation on the water pump, you must close the water inlet valve! If you forget, you will soon realize it
The water pump is located on the front of the engine, often driven by a belt. It is easy to locate, as it is connected to the water supply.
1 - Unscrew the cover
Use the right tool to avoid damaging the screws. Here on a Yanmar, the water pump is closed by 6 screws (flat head screwdriver).
2 eurosRemove the screws and remove the cover
Make sure that the screws do not fall into the bilge. Provide a small container to store them for the duration of the operation.
3- The spinning wheel has lost a blade!
Once the pump is opened, we see the cause of our malfunction. The impeller had stuck to the pump body during the winter. When we started it up again, one of the vanes broke off. This is a common occurrence.
4 euros Recover the fin
In our case, the broken piece of the vane got stuck in the pump outlet pipe. It was time to retrieve it before it went further into the engine.
5 euros Put the new spinning wheel back in place
The wheel can be removed and reinstalled by simply aligning the key in the center.
6 euros Pay attention to the direction of rotation indicated on the cover
To prevent the vanes from twisting backwards on the first turn, they are predisposed in the correct direction when the impeller is installed. To do this, check the direction of rotation, which is indicated on the pump cover.
7 euros Put the O-ring back in place.
The O-ring is replaced, greasing it to prevent it from drying out. Older water pumps sometimes close with a paper seal. In this case it should be changed at the same time as the impeller.
8 euros Screw the cover back on
Reassemble the cover by successively tightening the screws. Do not start by tightening a screw to the bottom. The load must be distributed gradually on the cover so that it sits well on the seal.
Make sure at start-up that you don't have any water leaks and that the engine "spits" its water well. And have a good navigation!
