Impeller frustration

westhinder

westhinder

Well-Known Member
Joined
15 Feb 2003
Messages
2,656
Location
Belgium
Visit site
Does anyone have a fast and easy way of removing the impeller from a raw water pump on a Yanmar 3JHE3?
The pump is mounted on the port side of the engine, tucked under and behind the alternator, facing aft. This means that it is not easy to reach and I have not yet found a way of putting real power on the impeller to slide it out.
It has taken me half an hour of fumbling with bent fine pliers and a screwdriver to finally remove the offending impeller. The engineer who designed this probably never had to replace an impeller himself.
That can't be how it is meant to be? I used to remove and replace the impeller on my Perkins Perama in under two minutes. I shudder to think what would happen if I have to replace an impeller somewhere at sea in difficult conditions.
So I will be grateful for all practical suggestions
 
Now you have done it once it will be easier next time. You could work out whether you can rig a mirror to help and suggest buying a proper pair of bent nose bird beak pliers. Probably work being very assiduous in changing impellers in your case.
If you do have a failure and have a calorifier fitted then running the hot tap can cool the engine for a short while at low revs.
 
I know what frustration you are experiencing . I have a 4JH2E and this spring It took me 2 hours to change the impeller . After putting up with this for 15 years I took the plunge and purchased a jabsco compact. Impeller removal tool , part no 50070-0080 . Smallest and priciest one they do. And that just fits in .
Used it once and worked so far so good then.. And getting the thing back in I will be trying an old tin can cut in half with 2 j-clips with compressed impeller inside with lube and push it in .
Its a hell of a job tho .




QUOTE=westhinder;5538175]Does anyone have a fast and easy way of removing the impeller from a raw water pump on a Yanmar 3JHE3?
The pump is mounted on the port side of the engine, tucked under and behind the alternator, facing aft. This means that it is not easy to reach and I have not yet found a way of putting real power on the impeller to slide it out.
It has taken me half an hour of fumbling with bent fine pliers and a screwdriver to finally remove the offending impeller. The engineer who designed this probably never had to replace an impeller himself.
That can't be how it is meant to be? I used to remove and replace the impeller on my Perkins Perama in under two minutes. I shudder to think what would happen if I have to replace an impeller somewhere at sea in difficult conditions.
 
Last edited:
djc said:
And getting the thing back in I will be trying an old tin can cut in half with 2 j-clips with compressed impeller inside with lube and push it in .
Click to expand...
Have you tried a cable tie to compress the impeller? Works for me. (Different engine, but that shouldn't matter) Put it on before you cover the impeller in lube. :)
 
Not quite so inaccessible, but the one on my Yanmar 2GM20F also faces aft. I have fitted it with a speedseal face plate which helps but I still have to remove the pump first. I took the plunge and bought a complete replacement pump so in an emergency, I could just swap the pumps over. Still means removing and refitting but quicker than replacing the impeller.
 
I made a special tool which works on the same principle as the Jabsco extractor but is much smaller so that it can be used in the small gap between the pump anf the starter motor on my 4JH2 DTE.
 
It looks like I will have to bite the bullet and buy one of these impeller pullers, as I lack the skills to make my own. Thanks for the suggestion.
As far as inserting the impeller is concerned, a tie wrap fastened around the impeller works for me.
Thanks for the replies.
 
On my 2GM20FM, if you undo the mounting bolts on the pump, you can twist the pump round to face the front without undoing the hoses. This makes impellor replacement much easier.
Don't know if this also applies to the 3JHE.
I've never had to use a device to compress the vanes, perhaps I've got strong wrists.
 
Both yanmar and Volvo did offer a jacking tool that is designed to us with an impeller that has an internal thread in the boss but the impellers seem to be obsolete DOH!

Yanmar stopped offering the threaded one not sure if Volvo still do one
 
Last edited:
You could make up a simple tool if your impeller has a threaded end section on end nearest the plate. Pretty easy to check with a camera or by touch.

I made one up for a couple of pounds before discovering that Yanmar show a similar design in one of their manuals (so re-inventing the wheel).

Instructions here: http://www.mistroma1.webspace.virginmedia.com/ImpellerExtractorTool.html

You only need a brass blanking plug, setscrew, nut, plob of araldite and a hand drill. Not exactly rocket science. I'd had added a wing nut to a longer setscrew to make it easier to use. However, the pump is easy to reach on my engine so not worth the effort. I envisaged a large wingnut screwed up to the head and locked there with another nut, should be easy to turn.
 
Last edited:
westhinder said:
It looks like I will have to bite the bullet and buy one of these impeller pullers, as I lack the skills to make my own. Thanks for the suggestion.
As far as inserting the impeller is concerned, a tie wrap fastened around the impeller works for me.
Thanks for the replies.
Click to expand...

Be careful, the Jabsco puller is no use at all for my Yanmar as it is simply too long to get in between pump and starter motor, hence my home made one which is clamped to the impeller by means of a screw clamp at 90 degrees to the axis of the impeller shaft.
 
If you want to stay sane remove the pump - and fit the impellor on the bench !

Its only two hoses - you can check if the spigots are furred up - and clean them easily if so.
Engine mounted pumps are usually just a few hex head bolts to the timing case.
 
That is the reason I did NOT buy a Yanmar when I re engined a few years back! As mentioned the Perkins Perama is front mounted and very easy to remove. I also bought a cheap pair of long nose pliers, heated the ends to soften them and bent them inwards so that you can easily grab the centre rubber boss and remove it. Whether you have room on your Yanmar to do this I don't know. To make it easier to get the screws undone, replace the backplate and screws with a SPEEDSEAL kit, an excellent piece of kit and makes the job much easier(or on my current Beta engine, replaced the fiddly screws with Knurled Thumb Screws - easily bought off Ebay)
 
Thanks again for the suggestions.
A few more thoughts:
Removing the pump in order to replace the impeller is not what I'm after. I feel it should be possible to replace the impeller quickly if it gives up the ghost say in a harbour approach. That is not the time to disassemble the engine.
Unfortunately the impeller does not have a threaded end, otherwise an extractor would not be too difficult to make.
I will certainly check whether there is enough space for the Jabsco puller.
I can only echo what has been said about the Speedseal, I fitted one when I bought the boat.
 
Pity it isn't threaded. I believe that the 3JH4E uses the same pump I have and thought it might be the same for your engine. Also possible it was changed at some point for an impeller without the thread. I was told that some have it and some don't and my original and Yanmar spare both have the threaded part. I'm going to make a point of sourcing a genuine part in UK (my wife's godson is a Yanmar dealer) or keeping an eye out for the correct one in Spain. The thread makes it a doddle to change the impeller. However, it's not critical on my setup as the pump is at the front. Having the threaded puller just means I can lean in and do it without removing the rather heavy companionway steps. So good if I need to do it in a hurry at sea.

EDIT: Might be worth trying to get a replacement with threaded end if you haven't bought a spare already. The DIY version in my link is tiny vs. others people are showing. It has +ve grip, easy to use and costs about £2 plus 30 minutes time.
 
Last edited:
You must log in or register to reply here.

Share this page

Top