MD2020 saltwater pump
- Thread starter Neeves
- Start date
Neeves
Well-Known Member
I thought sailbleu's post added something to our , mine at least, knowledge. I had noted the application for which he used it was different to our assembly - but that did not negate from the idea. However I did wonder if you added the SKF Speedi-sleeve in the 'middle' of a shaft with other components you needed to add first how the other components might slip over the enlarged shaft (slight though it might be) where the sleeve had been installed.
Our wear appears to be at the oil seal, so the water seal needs to be installed first and over where the sleeve will be. First time one can install the seal first - but thereafter the sleeve might damage the seal when you install it - maybe simply install 2 sleeves?
Jonathan
Our wear appears to be at the oil seal, so the water seal needs to be installed first and over where the sleeve will be. First time one can install the seal first - but thereafter the sleeve might damage the seal when you install it - maybe simply install 2 sleeves?
Jonathan
Ruffles
Well-Known Member
Re: Ok So how do I start
The orientation of the seals are so that the high pressure side increases the force on the shaft. Otherwise it will leak.
Forget the VP prices! They are standard metric oil seals - inside dia x outside dia x width - mine were 12x24x7 for an MD2030
Though you probably want to shell out for one with a stainless spring for the sea water side. The brown Viton ones are suitable and double seals will move the wear point. But even then they were only £6! The spares are still in the tool kit.
The orientation of the seals are so that the high pressure side increases the force on the shaft. Otherwise it will leak.
Forget the VP prices! They are standard metric oil seals - inside dia x outside dia x width - mine were 12x24x7 for an MD2030
Though you probably want to shell out for one with a stainless spring for the sea water side. The brown Viton ones are suitable and double seals will move the wear point. But even then they were only £6! The spares are still in the tool kit.
Neeves
Well-Known Member
Re: Ok So how do I start
Where did you get your Viton seals? Double seals? - can you explain, for those of us intellectually challenged!
Jonathan
Where did you get your Viton seals? Double seals? - can you explain, for those of us intellectually challenged!
Jonathan
johnphilip
Well-Known Member
Re: Ok So how do I start
Thanks for peoples' advice, re-assembly now almost complete, I found the force fit of bearings eased considerably by appropriate use of freezer and hot water to increase tolerances.
One last doubt. On the Volvo diagram
http://www.marinepartseurope.com/uk/en/volvo-penta-explodedview-7740690-26-4153.aspx
Parts 6 and 9 appear wrong. Either part 6 must be reversed so the prongs form a spacer over O ring 9 or they must be put in in the opposite order to get the same effect. Any comment on Volvo's accuracy?
I believe the O ring should be in the centre of the openings in the housing so any drips, be it from oil or water seal cannot run right along the shaft.
The disassembly was done by a mechanic friend who had the kit and/or the nerve to hit it hard enough to remove the gear from the shaft. He also, to my grateful surprise, dismantled the rest, carefully putting the components on a cable tie to record their positions. He recorded that part 6 was fitted in the reversed position from the VP drawing.
Thanks for peoples' advice, re-assembly now almost complete, I found the force fit of bearings eased considerably by appropriate use of freezer and hot water to increase tolerances.
One last doubt. On the Volvo diagram
http://www.marinepartseurope.com/uk/en/volvo-penta-explodedview-7740690-26-4153.aspx
Parts 6 and 9 appear wrong. Either part 6 must be reversed so the prongs form a spacer over O ring 9 or they must be put in in the opposite order to get the same effect. Any comment on Volvo's accuracy?
I believe the O ring should be in the centre of the openings in the housing so any drips, be it from oil or water seal cannot run right along the shaft.
The disassembly was done by a mechanic friend who had the kit and/or the nerve to hit it hard enough to remove the gear from the shaft. He also, to my grateful surprise, dismantled the rest, carefully putting the components on a cable tie to record their positions. He recorded that part 6 was fitted in the reversed position from the VP drawing.
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vyv_cox
Well-Known Member
Re: Ok So how do I start
The diagram says that part No.6 is obsolete. When I last bought a repair kit it was not included and it is not in the pump that I had rebuilt recently. The O-ring is there as a 'flinger' to throw any water that gets through the seal outwards rather than it running into the bearing.
The diagram says that part No.6 is obsolete. When I last bought a repair kit it was not included and it is not in the pump that I had rebuilt recently. The O-ring is there as a 'flinger' to throw any water that gets through the seal outwards rather than it running into the bearing.
VicS
Well-Known Member
Re: Ok So how do I start
And in some pumps that only ever had an O ring between the seals instructions are to omit even that!
Basically i think you have to refer to the latest instructions or service bulletin for each type of pump.
And in some pumps that only ever had an O ring between the seals instructions are to omit even that!
Basically i think you have to refer to the latest instructions or service bulletin for each type of pump.
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vyv_cox
Well-Known Member
Re: Ok So how do I start
I wonder whether that has to do with the type of vent on the pump body. It was suggested to me recently that the very small drain hole in the pump on a Bukh pump can easily be blocked and should be cleaned regularly with a wire or needle. (I have modified that section on my website accordingly). A flinger would not be very useful there. Conversely, the Johnson pump on my Yanmar has two very large ports and the yard that pressed the bearings out of my pump this August put the flinger in when they partly rebuilt it. Your diagram shows no ports, maybe a small drilling, hence no flinger?
And in some pumps that only ever had an O ring between the seals instructions are to omit even that!
Basically i think you have to refer to the latest instructions or service bulletin for each type of pump.
I wonder whether that has to do with the type of vent on the pump body. It was suggested to me recently that the very small drain hole in the pump on a Bukh pump can easily be blocked and should be cleaned regularly with a wire or needle. (I have modified that section on my website accordingly). A flinger would not be very useful there. Conversely, the Johnson pump on my Yanmar has two very large ports and the yard that pressed the bearings out of my pump this August put the flinger in when they partly rebuilt it. Your diagram shows no ports, maybe a small drilling, hence no flinger?
VicS
Well-Known Member
Re: Ok So how do I start
Yes I beleive the reason for no longer fitting the O ring was that it could obstruct the drain hole.
I think the drain hole i s not shown on the diagram merely because the purpose of the diagram is to illustrate what is said i t he text .Namely not to fit the O ring.
The diagram, and the earlier one, comes fro the MD11C/MD17C 'shop manual. There is certainly a drain hole in the MD11C pump!
Yes I beleive the reason for no longer fitting the O ring was that it could obstruct the drain hole.
I think the drain hole i s not shown on the diagram merely because the purpose of the diagram is to illustrate what is said i t he text .Namely not to fit the O ring.
The diagram, and the earlier one, comes fro the MD11C/MD17C 'shop manual. There is certainly a drain hole in the MD11C pump!