MD2020 raw water pump removal question

[essexsj]

Might be a novice question but should the engine oil be drained before attempting removal of raw water pump for the MD2029, or will there just be small amount of residual oil lubricating it whilst engine is running in normal operating conditions?
Thanks.

 

[xyachtdave]

No need to drain the oil, brace yourself the rear nuts are a complete PITA to remove!

 

[essexsj]

Thank you. Inherited this issue from my late father… not long before he passed away he told me of the problem he had trying to remove it. He gave up and was going to engage an engineer to do the job for him, but never got around to it before becoming ill.

 

[xyachtdave]

Sorry to hear that. In my installation access from the left side of the engine isn't great, I removed the engine mount on that side to improve access.

I'd allow a morning to get it off, with a tea break around the time you feel like using a club hammer!

 

[Neeves]

I don't recall the spanner sizes (and its late, dark and we are in strict lockdown - so I'm not venturing to the mooring).

But

As mentioned the locating nuts are a bugger. I used a long socket, a short socket and cut down spanners. First you need to 'crack' the nuts, then you need to turn them, but there is no room to get a spanner on them - hence the cut spanners.

There are only 4 - but I think xyachtdave is gilding the Lilly - it needs great patience

This is what you are aiming to find!





I'm no expert, at all, but did remember to take some pictures. If I get it wrong - someone can add the details and corrections.

The geared end is 'in' engine, the right hand end takes the impeller. The two seals at the impeller end hold the raw water in and the other one 'secures' the oil. If I remember correctly (confirmation needed) - you need to take the gear off, gear puller, top of picture and then everything slides off (maybe you need the gear puller for the bearings as well. You will need to replace the 2 seals, they are not expensive - but buy them before you start. The shaft might be worn, at the seals, and then you might need a new shaft (I cannot advise). The housing that I have at the top of the picture - that's the engine end and 4 holes hold the studs (?) or bolts (don't recall) that are the bugger to remove.

If I'm right and you need to take the gear off, to access the bearings and seals, then you could use a wooden mallet with a wooden board with a hole in it (but a gear puller is more kind - and in every tool kit ).

It would be dead easy - on a work bench - I have to lie on top of the engine and remove mine 'up-side' down.

Along with the two seals buy some decent whisky - you can reward yourself when you finish.

Take care, stay safe

Jonathan

 

[essexsj]

I don't recall the spanner sizes (and its late, dark and we are in strict lockdown - so I'm not venturing to the mooring).

But

As mentioned the locating nuts are a bugger. I used a long socket, a short socket and cut down spanners. First you need to 'crack' the nuts, then you need to turn them, but there is no room to get a spanner on them - hence the cut spanners.

There are only 4 - but I think xyachtdave is gilding the Lilly - it needs great patience

This is what you are aiming to find!



View attachment 120665

I'm no expert, at all, but did remember to take some pictures. If I get it wrong - someone can add the details and corrections.

The geared end is 'in' engine, the right hand end takes the impeller. The two seals at the impeller end hold the raw water in and the other one 'secures' the oil. If I remember correctly (confirmation needed) - you need to take the gear off, gear puller, top of picture and then everything slides off (maybe you need the gear puller for the bearings as well. You will need to replace the 2 seals, they are not expensive - but buy them before you start. The shaft might be worn, at the seals, and then you might need a new shaft (I cannot advise). The housing that I have at the top of the picture - that's the engine end and 4 holes hold the studs (?) or bolts (don't recall) that are the bugger to remove.

If I'm right and you need to take the gear off, to access the bearings and seals, then you could use a wooden mallet with a wooden board with a hole in it (but a gear puller is more kind - and in every tool kit ).

It would be dead easy - on a work bench - I have to lie on top of the engine and remove mine 'up-side' down.

Along with the two seals buy some decent whisky - you can reward yourself when you finish.

Take care, stay safe

Jonathan

Thanks Jonathan, some great information there. My father had bought a complete new replacement pump and left it with a ‘sorry’ note for me ??.

Myself and brother-in-law have recently replaced the engine mounts on my Moody 27, so quite used to extreme access methods, although this does seem to be rather more challenging.

 

[wiggy]

Remove the front engine mount on the pump side and chock the engine up, greatly enhances access to the bolts on the rear.

 

[yotter]

The first time I removed the sea water pump on my MD2030 to change the oil seals, all went well apart from the 2 rear PITA nuts. All refitted, started engine, no water out of exhaust...... Then after some investigations removing coolant hoses and putting ends in buckets, found out the pump was going the wrong way, yes it is possible to fit it upside down. Was tempted to just swap the hoses, but removed the pump and refitted the correct way. I hope I will only do that once
Angus

 

[Daydream believer]

I forget the exact details but I have had to remove the pump on my MD2020 twice. There is a a bolt that goes through & one has to access it from the rear. This is a job to get into place & takes ages turning the spanner. So I cut a slot in the end of it so a thin screw driver fitted the slot. Then I could fit the screw driver down the bolt hole & wind the end of the bolt from the front into place before having to use a spanner for the final tighten.
I forget which bolt & what way round, but have a look & work it out. You will find it well worth the couple of minutes cutting the slot. It needs a long thin screwdriver & one needs to run the bolt in & out of the hole prior to assembly so it turns nice & easy.
It will be there for the next time you have to do it which as well as having to put the bolt back you will find that you can get the bolt out in a few seconds once the initial tension has been released.

 

[essexsj]

Got the water pump off at last - what a beast of a job!

Undid the two engine mount nuts and bolts from the bearer, and the two bolts from the engine block, pushed the unit back and wedged with a couple of slim screwdrivers, used a cut down 12mm open ended spanner to undo the rear thread bolts from the unit.

I presume I now need a gear puller to remove the old gear cog in order to add to the new one? or is there another method?

 

[Neeves]

What is wrong with the existing gear?

From memory, which may well be flawed:

You should be able to remove the complete assembly relatively easily. (you need to remove the impeller first and then then whole lot pulls apart (in your picture the shaft with gear and seals lifts out vertically). You do not need a gear puller for this stage. I recall it just pulled apart - it might have needed a light tap (with a wooden mallet).

You do need a gear puller to remove the gear, or cogged wheel.

But once you have the shaft, seals and cogged wheel removed (as one unit) you could conceivably make up a bit of beefy hard wood with appropriately sized holes and resting the cog on the hard wood - hammer out the shaft - with a wooden (or appropriate) hammer). In your picture the shaft is hammered down.

But wait till someone adds to the thread as I have not dismantled for some years.

The major wear portion is the shaft, I believe, at the seals and that is how the unit leaks - through the wear of the shaft at the seals. I believe new shafts are expensive. I think the unit is supplied by Johnson and they might be the best source of a new shaft. But you seem to have a new gear (don't quite understand how the gear could be damaged, looks fine in your picture) and if you have sourced a gear then that source should be good for a shaft (if needed).

I don't know how you check the shaft - micrometer? But reassembly to check if it leaks seems a night mare - if you then need to pull it apart - again.

For such a small item it does cause untold heartache.

Jonathan

 

[essexsj]

What is wrong with the existing gear?

From memory, which may well be flawed:

You should be able to remove the complete assembly relatively easily. (you need to remove the impeller first and then then whole lot pulls apart (in your picture the shaft with gear and seals lifts out vertically). You do not need a gear puller for this stage. I recall it just pulled apart - it might have needed a light tap (with a wooden mallet).

You do need a gear puller to remove the gear, or cogged wheel.

But once you have the shaft, seals and cogged wheel removed (as one unit) you could conceivably make up a bit of beefy hard wood with appropriately sized holes and resting the cog on the hard wood - hammer out the shaft - with a wooden (or appropriate) hammer). In your picture the shaft is hammered down.

But wait till someone adds to the thread as I have not dismantled for some years.

The major wear portion is the shaft, I believe, at the seals and that is how the unit leaks - through the wear of the shaft at the seals. I believe new shafts are expensive. I think the unit is supplied by Johnson and they might be the best source of a new shaft. But you seem to have a new gear (don't quite understand how the gear could be damaged, looks fine in your picture) and if you have sourced a gear then that source should be good for a shaft (if needed).

I don't know how you check the shaft - micrometer? But reassembly to check if it leaks seems a night mare - if you then need to pull it apart - again.

For such a small item it does cause untold heartache.

Jonathan

Hi Jonathan, thank you for reply.
I have a complete replacement water pump, however it does not come with a gear… hence the need to remove from old.
My father passed away so cannot ask why the need was to replace but there was a definite reason to do so.

 

[Neeves]

Ah!

But there is nothing wrong with the gear, which was my interpretation. It appears your father had a problem with the pump, bought a new one (minus gear) and you are replacing the old pump with new and using the old gear on the new pump. Sounds straight forward to me now

As I said in my post No 11 - its actually very simple to take the gear off - so don't worry - but I simply don't remember which way round it came apart. I suspect your father had either an oil or water leak, or both (the shaft was worn) and decided to replace the lot.

Now - you have an old pump and the only bit you need is the gear (to add to the new pump). If you hear nothing useful (seems unlikely that no-one will offer help) then I'd have a look at the old pump you have taken off and check which is the obvious way to dismantle. I think that a few gentle taps with a wooden mallet for the impeller end of the shaft will remove the complete shaft assembly (because the gear will be in the way other wise). I am fairly sure the gear comes off the other way - hammer the thread apart of the shaft. I have a set of gear pullers (bought very cheap in HK 25 years ago) - but not much use to you as I am in Sydney

I'm surprised that the new pump did not come with assembly/disassembly instructions - but maybe they are in a pile of paperwork somewhere else.

From memory you need 2 new seals, unless they are on/in the new pump already

If you are not in a hurry (and no-one comes to your aid) - I have the workshop manual for the MD2020 - I can look there - but I will not be on our boat till early next week and will be unable to advise until mid week when I get back home.

You could try google - Johnson water pump MD2020

Jonathan

I had a quick look using google and there are a number of exploded drawings of the shaft assembly

Water pump kit for Volvo Penta MD2010 MD2020 MD2030 MD2040 D1-13 D1-20 3593659 | eBay

and it looks as if the shaft taper allows the gear to come off the threaded end - so in your photo the shaft is hammered or pushed down.

 

[essexsj]

All done. Thanks for everybody’s comments.