Access to the impeller on a 456

KD3PC · Jan 23, 2013

remove the whole pump, and change the impeller

use a mirror, old mechanics trick, but tough to get your directions straight

access hole made that will allow you to get to it correctly

best of luck, and it will result in at least one broken finger, perhaps two, if you do it in rolling seas, been there done that.

Bowedtoothdoc · Jan 23, 2013

kingsailor said:
On my 2002 456 the impeller is on the non-working side of the engine (4JH3-TE) against the bulkhead, facing back and behind the alternator. It is nearly impossible to reach. Has anyone found a reasonable solution on how to access it? I want to solve this before we head out to the Bahamas. I can't imagine trying to change this impeller in rolling seas on a hot engine.

Thanks

I am the same situation with my 450 and was intending to post about this.
I have seen some owners install an access panel in the shower, but my boat does not have one:cry:

artboas · Jan 23, 2013

Two things can help you

kingsailor said:
On my 2002 456 the impeller is on the non-working side of the engine (4JH3-TE) against the bulkhead, facing back and behind the alternator. It is nearly impossible to reach. Has anyone found a reasonable solution on how to access it? I want to solve this before we head out to the Bahamas. I can't imagine trying to change this impeller in rolling seas on a hot engine.

Thanks

On the newer Yanmar impellers, they have threaded the shaft. You can make/buy a small tool that will aid with the extraction. Only works on genuine Yanmar impellers.
Once you have the cover off, replace it with a Speedseal cover.

I can't imagine what Yanmar was thinking when they put the water pump where it is. On the 49, its even harder to access

Steve Dion · Jan 23, 2013

I do not know the exact setup on your setup but we cut an access door in the port side of the engine compartment. This allow me to get a set of angle needle nose pliers into the access area to remove the impeller.

We also replaced the impeller cover with a Speed-Seal. This makes getting the cover on/off much easier. Speed-Seal also have some new teflon washers to make your impeller last longer.

PS: Our engine is the 3JH2E (similar access to impeller)

Mikem · Jan 23, 2013

On my 466 I have to remove galley doors, galley shelves, access panel, companionway stair assembly, and then I stare at the rear mounted behind the alternator water pump impeller. The thought of dropping a screw under the engine is unnerving. I will have to take another look at removing the whole pump and then changing the impeller. I cannot imagine doing this in any kind of a sea state with a hot engine. Geez.

Don12364 · Jan 23, 2013

This has been extensively, and not infrequently, debated here previously. I gave my own solution but most fit the proprietary SpeedSeal which is held in place with thumbscrews so only needs fingers to change the impeller.
http://www.speedseal.com/SpeedsealLife/Lifetechdetails.html

Buck420 · Jan 23, 2013

kingsailor said:
On my 2002 456 the impeller is on the non-working side of the engine (4JH3-TE) against the bulkhead, facing back and behind the alternator. It is nearly impossible to reach. Has anyone found a reasonable solution on how to access it? I want to solve this before we head out to the Bahamas. I can't imagine trying to change this impeller in rolling seas on a hot engine.

Thanks

I have several friends with 456's.
Although it is possible to lean over the engine to replace the impeller, it is very difficult to do.
The only practical way of dealing with this problem is to cut an access panel in the shower as Bowedtoothdoc mentioned.

gillesgiv · Apr 2, 2013

I changed the impaler on Ceilidh, Hunter456 passage center cockpit 2003. Pain in the ass... First remove the belt and alternator. Second remove the 4 screws on the impaler cover. Third you need an impaler extractor and it is far and difficult. I never understood how people making a boat would not think of a better plan and configuration. The option of cutting an opening in the tub sounds ok but you are going to be far back and im not sure the access will be good.

rtmccue · Apr 2, 2013

On my 2000 450 I had a panel installed. Don't remove the pump you have to take the mount out. You can change it if you take the alt off and I use a needle pliers that have a round end , from MA C tools.

artboas · Apr 7, 2013

Really, really bad design

rtmccue said:
On my 2000 450 I had a panel installed. Don't remove the pump you have to take the mount out. You can change it if you take the alt off and I use a needle pliers that have a round end , from MA C tools.

If you guys think you have problems, on 49 the engine is mounted sub-floor.
It is a full day's job.
I am going to design & build a custom tool for this.
My goal is to have impeller change over in under 30 minutes without pulling alternator, etc., etc. I think, based on preliminary design This is possible.

Stay tuned ......

seadaddler · Apr 7, 2013

WOW

Thank goodness my 07 H-36 is so easy to change the forward facing impeller cover and my stairs remove away to work on the whole engine.
Another good reason to stay with my H-36 which we love and not go bigger,so easy to work on most anything and well designed model for storage easy sailing and just all around cruising,my P Gen iseveen easy to work on.
I did change the engine oil and filter and Gen oil and change the impeller yesterday in less than an hour.
Good thing we have this forum to help out with these

repairs.
ick