2GM20 Yanmar water pump. Advice needed.

Seakindly

Seakindly

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Grr - pump in bits. Looks like I need a new shaft seal - shredded - and a dealer I'll visit tomorrow says I'll almost certainly need a new shaft as well. "looks alright to me I say" - he says -'even the slightest mark will cause leak'. Now I note shafts cost over £50 quid and dealers are out of stock for a week. Any experienced DIYers advise? If I can't see any grooves -do I really need a new shaft? Secondly -the bearings are not as free as they could be -so I may as well replace them -but the manual says use a 'universal press-plate and arbor press'. Well I ain't going to get that in B&Q, whatver it is. Is there any other way to get the bearings off to replace 'em? They are affordable, thank goodness -a new pump is hundreds!
 
i rebuilt my pump with new bearings and seals for less than 20 quid, i used the online bearing supplier simplybearings.co.uk use the numbers on the bearings and on the saels , to remove the bearings heat the casing with a hot air gun and bang them out whilst holding the pump in a rag.
 
See whether the dealer will do it for you. Had the seals replaced on my 1GM for not a lot of money because the shaft was not damaged. same with bearings. He will be able to press the old ones off and replace them. Guess you will have to rely on his expertise about whether it can be done with your shaft.

Just checked the manual. Shaft diameter at oil seal is 10mm permitted wear is .1mm (0.3937 and 0.3898 in old money).

Hope this helps
 
[ QUOTE ]
i rebuilt my pump with new bearings and seals for less than 20 quid, i used the online bearing supplier simplybearings.co.uk use the numbers on the bearings and on the saels , to remove the bearings heat the casing with a hot air gun and bang them out whilst holding the pump in a rag.

[/ QUOTE ]

This man has obviously had an old car or motorcycle. Absolutely right - you can but the bits at an engineers bearing supplier (yellow pages) and fit them yourself.

However, these pumps wear on the front face plate and also the back surface, and the hum (replaceable) goes too.
 
Your decimal placings are wrong and how do you get two different figures for one measurement? 0.1mm =0.0039" or 4 thou.
 
I have had pump shafts made in stainless for a very small fraction of the cost for the OEM part.Any engineer will make one for you.However if you can´t detect a groove you may get away with just fine sanding the shaft and installing new seals.new bearings should not be a problem they're standard metric ones.Remember that at least the impeller side seal must have a stainless spring.
 
If you need bearings pressed out, visit a local garage where there's a big pile of Rollie buts outside with greasy prints all over them (i.e Not somewhere where they wear gloves and use a computer.

They will usually press bearings for 10 B&H or a £5er which for the hassle of what it is to do is well spent and only takes a couple of minutes.

Bearing press is basically a bottle jack in a frame, the bottle jack when pumped up, presses evenly the bearings in or out against it's own frame
 
By cheating and copying off the table on p7-10 of the official Yanmar manual.

And it is right
10.0 - 9.9 = .1mm

0.3937 - 0.3898 =0.0039 inches = .1mm (actually .9906mm to be precise)

Just trying to be helpful so that the poster could measure before going to the dealer.
 
Sorry, did get the decimal point in the wrong place this time - the last measurement should be 0.09906mm.

Must get some more accurate fingers!
 
Sorry, my fault, I mis-understood your initial post, you were correct and i'm just going to have my pudding ......a big slice of humble pie! /forums/images/graemlins/blush.gif
 
Was it leaking before? If not there is your answer?
Also the other factor is how much will it leak, if it only dribbles a little when your motoring and not sailing it will take weeks before you hit the bilge pump button. As long as it pumps water it will cool your engine and exhaust that is the real test.
Regardig bearings if there is no play and there is no squealing, again what is the problem?

If you are changing bearings as I have just done with my freelander transmission chuck the internal bit in the freezer and the outside bit in the oven at about 100 degrees then they will tap in or press in with a vice.
 
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'Hum'? um...cam? Sorry - I did have an old brit bike but 'hum' means nowt to me...wottisit?
hh

[/ QUOTE ]

Sorry - senile dyslexia. Hum is short for hump ie the lump the impeller runs over and which makes it work as a pump.

Thought you must have had an old brit bike. Well remember removing bushes and bearings from Norton engine cases with the judicious (and when that failed - vigorous) use of heat.
 
I bought a spare pump from the USA (much chepaer than a shaft only in the UK) and then took the old pump to pieces and repaired. It is not too difficult.

The local Yanmar service people previously changed the shaft - twice in 8 years - when the pump dribbled from the hole in the bottom (designed to allow water out and not go into engine oil). So if it wasn't leaking, the shaft was probably OK.
 
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