Removing rear wear plate from sea water pump?

LittleSister

LittleSister

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Tomorrow I'm planning to replace the (as yet unseen) wear plate and (rather worn) front cover of my Johnson F5B cooling sea water pump. The front cover is easy enough, but I'm wondering how easy it is likely to be to remove the old rear wear plate.

Once the impellor's removed, I'll just be seeing the face of it (or at least I will if I arrange a system of mirrors, as the pumps tucked away out of sight!). I'm just hoping there'll be some gap around the plate where I can get something in to prise it forward, and also that it won't be stuck in place by corrosion.

Can anyone offer any tips/encouragement/warnings?

I'm intending to be heading off in the boat immediately after doing this, and can't afford to be stuck half-finished.
 
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VicS said:
I expect the cam will have to be removed to release it.

Pump off job I suspect ,
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The pump is not coming off if I can help it! I've got enough on my plate as it is. May have to try to manage with cover change only.

kippers26 said:
is there a rear wear plate ?

I replaced the bearings and seals on my F5B pump and did not notice any rear plate
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There is one shown in the drawings and instructions for (both ancient and newer versions of) the F5B/9 pump in the Bukh manual and, as Vic has highlighted, there is one sold by ASAP.

Wish my pump was as visible and accessible as the one shown in your pic.
 
Reverse the cover plate, no need to worry about the lettering stamped into it.
To remove wear plate if you have one, simply remove the impeller and cam, then remove the plate.
Spares from ASAP
 
OK guys. I'm getting impatient now!:(

I know there's a wear plate - it's in the manual and I've already got the replacement part.

I know I can turn the cover over (but I'm fitting a new Speedseal).

I know I've got to remove the impeller.:roll eyes: and also the cam (thanks Vic, hadn't thought of that).

Now, back to the original question: how do I get the bloody wear plate out once I've got to it!
 
Once the cam is removed which is designed to secure the wear plate I think you will have little problem in persuading it to release. Mine was not jammed in but a loose fit so pretty much fell out. Incidentally I was also replacing the cam as it came with the 'wear kit' I had bought. I was surprised how much it was worn but it was over 25 years old. I think there has been discussion before on the theory but the correct size cam will pump more water than a very worn one. Best of luck. Cheers Bill
 
Billba said:
Once the cam is removed which is designed to secure the wear plate I think you will have little problem in persuading it to release. Mine was not jammed in but a loose fit so pretty much fell out. Incidentally I was also replacing the cam as it came with the 'wear kit' I had bought. I was surprised how much it was worn but it was over 25 years old. I think there has been discussion before on the theory but the correct size cam will pump more water than a very worn one. Best of luck. Cheers Bill
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Thank you, Bill. Illuminating and much appreciated.
 
I have a dry exhaust which means I know exactly how much water is going through my engine. I had to change everything, the difference was remarkable. However, there was enough to keep the engine at temp before the repair. Which means you might or might not get away with just faceplate reversal. Consider that back plate wear is likely to be the same as the impeller is squeezed between the two.
 
LittleSister said:
OK guys. I'm getting impatient now!:(

Now, back to the original question: how do I get the bloody wear plate out once I've got to it!
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If you're getting impatient, just think about us.

We're all wondering "Why doesn't he just get on with the job and see for himself how the plate comes out .... it's just a pump for Gawd's sake" :encouragement:

Richard
 
Be fair, gents! I know that the OP himself raised 'impatience', but I do have sympathy with his trying to get as much information as he can before beginning, particularly given the accessibility problem. It's a major virtue of the forum to be able to do so, surely? Anyway, perhaps he'll let us know how he got on ...
 
Hydrozoan said:
trying to get as much information as he can before beginning, particularly given the accessibility problem.
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Exactly so!

Anyway, here's how I got on:

Spirits rose when I saw that, to my surprise, I could actually reach the cam retaining screw. Took pump cover off. Couldn't get the impeller out! (Was easy on my previous boat.) My recently purchased ex
tractor tool was somewhere on the boat, but I couldn't find it. Oaths were uttered.

I put the new Speedseal cover on temporarily so that I could make a brief trip, intending to attack the rest of the job again later, after the impeller tool had come out of hiding.

Set off, and to my surprise the overheating problem was gone!

I don't think this is due to anything do with the pump or cover at all. The boat is new to me, and having discovered that the alternator was putting out about 16v, I replaced the regulator last week. I suspect the engine wasn't overheating at all, but the excessive voltage was making the temperature gauge over-read. [On the other hand, no noticeable change in the fuel gauge.]

So, I'll hang on to my wear plate as a lucky charm.

Thanks for all the suggestions. Sorry I got a bit exasperated.
 
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