Changing impeller on 41DS with Yanmar 4JH45 engine

[gerty]

Interested to hear from anyone who's already done this. Access to water pump flange is blocked by GRP plinth below engine front door/cover. Looks like plinth should be removable because it 'appears' to be held in place by five screws into the floor, however, when screws are removed it won't budge, it's also been bonded to the wooden floor panel that goes under the engine housing. I'm reluctant to force anything because it'll likely break the veneer on the floor in front of the engine housing but in the absence of any other solution. I may have to try and gently persuade them to part company. I presume the bond is Sikaflex but it's not a soft mastic, it's quite hard, any suggestions on how to break bond cleanly would be greatly appreciated.

[ohana]

Hi, I have the 439 so  can’t comment to your specific question unfortunately. I have loads of room to access the water pump on my 4JH5E.  Would only suggest that some modification is needed to give you fast access to the impeller, if it needs replacing in a hurry you will not want to have to start dismantling part of the surrounding cabin trims. 

[heatherina]

Hello
We have the same boat/ engine.
Just Changed the impeller on the water pump. There isn’t a lot of space but it not so bad. You should have a simple pulling tool that helps extract the old impeller. Lube up the new one and it goes in OK. You can try putting a cable tie around the new one to compress it. That will help fitting it.

Good luck.
Ian