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Water circulation problem.


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https://www.asap-supplies.com/jabsco-neoprene-pump-impeller-4568-0001

 

Note it's an impeller not an impella which probably made searching for it difficult.

 

Get two, as it's always good to have a spare ready to use.  Other suppliers exist but you need Jabsco 4568-0001-P or equivalent.

 

https://www.ebay.co.uk/itm/2-X-Impellers-for-Jabsco-4568-0001-Sierra-18-3075-Johnson-09-801B-Volvo-875575-3-/352835850564

 

These would do but you need the gasket and lubricant to reassemble the pump.  The lube is glycerine, don't use soap or oil on the neoprene impeller for best results.

 

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Any chance of a shot of the inside of the rear cover, the bit that fits against the impeller. There seems little apart from the ruined impeller that would stop it pumping in the photos so I would like to see just how badly that backplate is worn. Also too much grease from the back grease cap so the pump body could be bad;y worn a swell but I can guess about that when I see the shape of the shaft support hole in the pump's back plate.

 

I've used a squirt of washing up liquid to lubricate the impellors for years with no apparent harm.

 

Using that  "device" to flush the pipes is not very effective because you needs a lot of volume of water not a low volume at higher pressure. Anyway if the exhaust hose has started to delaminate it proves nothing, its when you go at higher speeds the exhaust gasses can get under  delaminating lining and block the pipe. Don't worry about this for now. When you get it sorted just keep an eye on the exhaust. If it starts hissing and suffers reduced water flow its time to look inside the exhaust hose but no now.

 

 

Edited by Tony Brooks
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On 21/07/2020 at 22:05, Tony Brooks said:

It seems, as is all too often the case, that the raw water pump draws raw water through the gearbox oil cooler. The copper pipe seems to pass through a bulkhead unless it fits directly into the back of the hull. If its the former then the strainer/sea inlet is behind the bulkhead. If its the latter then no wonder it wont pump water. The gearbox oil cooler core and/or the heat exchanger core are probably full of rubbish  from the water.

 

Any even slightly loose hose between raw water inlet and the raw water pump will reduce or stop the raw water pump output.

 

We still need to see where the raw water is drawn into the boat

I was going to make a similar comment. A common failure is the seal on the mud box/filter. It only needs to have a tiny gap letting air in and your water pump will no longer draw water. 

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TheBiscuits Thank you for the details and correction.

 

Tony I saw a water drop fall from the front part of the water pump and I think I might have noticed it a few times before.

 

When you say heat exchanger core do you mean the round tube with the thin copper pipes encased in it?

 

Photos to follow.

 

 

 

 

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15 minutes ago, marji said:

TheBiscuits Thank you for the details and correction.

 

Tony I saw a water drop fall from the front part of the water pump and I think I might have noticed it a few times before.

 

When you say heat exchanger core do you mean the round tube with the thin copper pipes encased in it?

 

Photos to follow.

 

 

 

 

Heat exchanger core - yes the small tubes. Push a length of suitably sized electrical cable through them. If you are careful you could use a bit of welding rod or straightened coat hanger but be carefull.

 

Re the pump drip. It may be just because the gland packing is worn or needs adjusting so that is the first thing to do AFTER you slacken the gland lock nut, unscrew the gland nut (the packing is inside the nut) and then see how much play there is between shaft and pump body. If its less than say 1mm reassemble the gland nut but tighten it up a little more than it was when you took it off. If the seal still leaks tighten it a little more but not too  much. If it still leaks you need new packing. I think The Jabsco Shop (Cleghorne & Wearing) will sell it.

 

If you want to get the pump drive belt off loosen the two bolts in the foot to allow the pump pulley to tip  downwards towards the crankshaft pulley. The bracket the pump is bolted to may  be secured to the engine by bolts in slots. that should also allow you to move the pump.

 

 

 

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Tony I can 100% confirm that the core had impeller rubber in it but clear of any weeds, in fact the whole system was clear of weeds, I held the Heat exchanger core to the sun after using a fine jet to clean every tube and can confirm every tube was clear.

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The impellor has shredded because it was running dry, this can only mean that the water blockage was before the pump.

 

What is before the pump ?

 

1) Your wonderful pipe end filter.

2) The pipe leading into the boat.

3) The pipe from the inside of the boat to the oil cooler

4) The oil cooler

5) The pipe from the oil cooler to the pump.

 

Maybe the external filter picked up a plastic bag which was sucked onto the filter and stopped the water flow, once the impellor stopped working the suction would drop and the bag fall off the filter and float away (I have had it happen)

 

Carefully check each component (numbered 1 to 5) and if they are all clear (and clean) then rebuild the pump and start to work forward component by component (you have already made big inroads into the job by disassembly of the heat exchanger).

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The pump cover looks well torn up. reface it by rubbing it on a sheet of emery paper in a glass plate so that its flat.

You seem to have got to the bottom of the problem, lost strainer, pulled rubbish in,  blocked somewhere, pump ran dry wrecking impeller which threw bits into the heat exchanger matrix.

Pump was due for overhaul anyway.

TD'

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1 minute ago, Alan de Enfield said:

The impellor has shredded because it was running dry, this can only mean that the water blockage was before the pump.

 

What is before the pump ?

 

1) Your wonderful pipe end filter.

2) The pipe leading into the boat.

3) The pipe from the inside of the boat to the oil cooler

4) The oil cooler

5) The pipe from the oil cooler to the pump.

 

Maybe the external filter picked up a plastic bag which was sucked onto the filter and stopped the water flow, once the impellor stopped working the suction would drop and the bag fall off the filter and float away (I have had it happen)

 

Carefully check each component (numbered 1 to 5) and if they are all clear (and clean) then rebuild the pump and start to work forward component by component (you have already made big inroads into the job by disassembly of the heat exchanger).

I have just organise everything you just said with photos, I am now quite sure the hose from the back of boat to oil cooler is the main inlet and that oil filter has two mesh filters that will catch anything before it gets into the pump, this explains why I have only found rubber in the system and no weeds at all.

 

But remember going back in this thread I did say I after moving my boat notice it never had the end hose filter on the pipe, and that I undone the hose area where the pipe joins both sides of the oil cooler and there was weed/algae on the first mesh and the second mesh was clear other side of the oil cooler.

 

I will post these photos once Tony has got back to me regards the wear on the cover plate. 

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12 minutes ago, Tracy D'arth said:

The pump cover looks well torn up. reface it by rubbing it on a sheet of emery paper in a glass plate so that its flat.

The bearing face for the impellor is set lower than the flange so I doubt that cleaning the face using glasspaper and a sheet if glass will make any improvement, and the gasket will take up any minor damage between the pump body & face plate anyway.

 

It is the recessed face that is a 'bit chewed up' and needs 'looking at'.

 

 

36 minutes ago, marji said:

Pump photos, I do have more of the whole pump if needed.

When you order a new impellor make sure you order the 'kit' not just an impellor.

 

The kit will give you all the bits you need including gaskets, shaft key, O' Rings and a tube of lubrication (to stop it burning out when you start the engine because it is running dry)

 

Just an example :

Johnson Pump Impeller 09-801B

 

 

Edited by Alan de Enfield
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3 minutes ago, Alan de Enfield said:

The bearing face for the impellor is set lower than the flange so I doubt that cleaning the face using glasspaper and a sheet if glass will make any improvement, and the gasket will take up any minor damage between the pump body & face plate anyway.

 

It is the recessed face that is a 'bit chewed up' and needs 'looking at'.

 

 

When you order a new impellor make sure you order the 'kit' not just an impellor.

 

The kit will give you all the bits you need including gaskets, O'Rings and a tube of lubrication (to stop it burning out when you start the engine because it is running dry)

 

 

When I took of the impeller cover there was no O'Ring but it had two gaskets fitted both in good condition.

Edited by marji
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1 minute ago, marji said:

When I took of the impeller cover there was no O'Ring but it had two gaskets fitted both in good condition.

OK, mine has an O Ring.

 

It is best practice to always replace gaskets when reassembling, it avoids a lot of potential leak problems and you are going to be spending so much money on that boat, a few pennies more to do the job properly is really worth it.

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As Tracy says the end plate is well worn, this is perfectly normal as the years go by. The face of the pump body the the side of the impellor will be similarly worn so both together tends to stop the pump priming. The back cover was perfectly flat when it was new. The recess where the impellor runs is wear so I am with Tracy on this. A sheet of emery paper on glass to give flat surface and start rubbing in a circular motion, twisting the cover in your hand every say 10 circles to even out any tendency to make the face angled. Do this until its flat.

 

Some pumps have a wear plate inside the body of the pump trapped behind the cam but I don't think yours does. If it did you could reverse that but no such luck I think.

 

I can't see any signs of a worn oval hole in the end plate but am not so sure about pump body - too much grease and much in there. One image seems to indicate the shaft sat an an angle in the body but it could just as well be camera angle. This is why I keep asking about lift or play between shaft and pump body.

 

Never, ever fit more than one gasket. If you do it tends to prevent the cover making a good seal to the impellor so again a lack of priming and reduced flow.

Edited by Tony Brooks
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3 minutes ago, Alan de Enfield said:

OK, mine has an O Ring.

 

It is best practice to always replace gaskets when reassembling, it avoids a lot of potential leak problems and you are going to be spending so much money on that boat, a few pennies more to do the job properly is really worth it.

Oh no I was not suggesting to reuse them just was a general bit of information.

 

Main blockage wedged in hard.

 

 

main wedge.jpeg

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5 minutes ago, Tony Brooks said:

As Tracy says the end plate is well worn, this is perfectly normal as the years go by. The face of the pump body the the side of the impellor will be similarly worn so both together tends to stop the pump priming. The back cover was perfectly flat when it was new. The recess where the impellor runs is wear so I am with Tracy on this. A sheet of emery paper on glass to give flat surface and start rubbing in a circular motion, twisting the cover in your hand every say 10 circles to even out any tendency to make the face angled. Do this until its flat.

 

Some pumps have a wear plate inside the body of the pump trapped behind the cam but I don't think yours does. If it did you could reverse that but no such luck I think.

 

I can't see any signs of a worn oval hole in the end plate but am not so sure about pump body - too much grease and much in there. One image seems to indicate the shaft sat an an angle in the body but it could just as well be camera angle. This is why I keep asking about lift or play between shaft and pump body.

 

Never, ever fit more than one gasket. If you do it tends to prevent the cover making a good seal to the impellor so again a lack of priming and reduced flow.

Ok Tony I am going to degrease the pump now, and there is no play or lift between shaft and body its quite solid and spins well.

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5 minutes ago, marji said:

Ok Tony I am going to degrease the pump now, and there is no play or lift between shaft and body its quite solid and spins well.

 

That is good news. Looks like it will   work if you just reassemble it but while its apart its best to flatten the end cap.

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FWIW I have just checked the Xylem Jabsco site. The pump is out of stock (I think no longer available), the end plate is out of stock (ditto) but they do have impellors and gland packing. The packing costs £8 so i could see some modified stern gland packing being put to use:)

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46 minutes ago, marji said:

Oh no I was not suggesting to reuse them just was a general bit of information.

 

Main blockage wedged in hard.

 

 

main wedge.jpeg

BINGO!   That would account for the problem, is there any more elsewhere though?

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1 hour ago, Alan de Enfield said:

The bearing face for the impellor is set lower than the flange so I doubt that cleaning the face using glasspaper and a sheet if glass will make any improvement, and the gasket will take up any minor damage between the pump body & face plate anyway.

 

It is the recessed face that is a 'bit chewed up' and needs 'looking at'.

 

 

 

 

 

 Lapping the cover down is a recommended repair unless it is possible to reverse it, not in this case obviously.

Wear in the other face inside the impeller ( not impellor ) recess is sorted the same way by lapping the face of the pump body.

Sometimes, rarely, there is an alternative impeller that is wider which will fit, often with more than one gasket fitted to compensate for it being too wide. Bit of a bodge but if you can't buy a new pump.......................

TD' 

Edited by Tracy D'arth
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20 minutes ago, Tracy D'arth said:

Lapping the cover down is a recommended repair unless it is possible to reverse it, not in this case obviously.

I know and have done it many times, what I was trying to say is that the damage is 'below the surface level' of the cover (recessed), so laying the plate flat on a sheet of glass will not touch the damage inside the recess, only the edges (around the screw holes) of the plate.

 

There does appear to be a noticeable wear 'step down', hopefully you can see what I mean, (and, I'm also wondering what that circular 'blob' is at 4 o'clock)

 

1.jpeg

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4 minutes ago, Alan de Enfield said:

I know and have done it many times, what I was trying to say is that the damage is 'below the surface level' of the cover (recessed), so laying the plate flat on a sheet of glass will not touch the damage inside the recess, only the edges (around the screw holes) of the plate.

 

There does appear to be a noticeable wear 'step down', hopefully you can see what I mean, (and, I'm also wondering what that circular 'blob' is at 4 o'clock)

 

1.jpeg

The BloB is water!

Don't get what you are saying Alan, the whole of the cover needs lapping down till is flat all over, there is no original recess around the bearing hole or the edge, its all wear by the impeller.

TD'

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5 minutes ago, Alan de Enfield said:

I know and have done it many times, what I was trying to say is that the damage is 'below the surface level' of the cover (recessed), so laying the plate flat on a sheet of glass will not touch the damage inside the recess, only the edges (around the screw holes) of the plate.

 

There does appear to be a noticeable wear 'step down', hopefully you can see what I mean, (and, I'm also wondering what that circular 'blob' is at 4 o'clock)

 

 

It will eventually once the part where the gasket sits is lapped away, He will just have to be patient. The blob looks like water to me.

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