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southy1981

Joined:

Sep 10

Posts: 49

southy1981 says:

Oil leak from water pump

Hi Guys, hopefully you can help.

I had noticed oil pooling up at the bottom of my waterpump. Defo oil not water before you ask.

I have a link to a pic that might explain where i am coming from:

 

http://www.yamahascooterspares.co.uk/spares/epc2.asp?modelID=9587&PageiD=5&m=YAMAHA+YP250+MAJESTY++1997+WATERPUMP&uID=0

 

Firstly i thought it was seal number 11 that might of gone, so replaced it and thought that would be the end of it.

But it isn't, the  oil is still coming from somewhere and is defo around the waterpump.

I believe the oil is coming from the tattle hole on the water pump, which would make me believe that seal number 7 is letting oil past.

So far i do not have oil in water and water in oil.

I have looked into getting a complete waterpump rebuild kit.  But these are only availible for models made after 2000, even though all the websites say it will fit pre 2000 models.

If anyone can shed some light on this it would be apprectiated, or whethere they can get their hands on a rebuild kit that will fit a 1998 Yamaha Majesty 250?

 

Thanks in advance.

Andy

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  • Posted 315 days ago (08 July 2012 18:56)

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smidget

Joined:

Nov 07

Posts: 2050

smidget says:

Hi

The only link between oil and water is sealed by 'oil seal number 7', but this allows oil into the engine coolant system.

If you do change a water pump seal it is best to change all seals at the same time, and replace the gaskets as well.

When changing the water pump water seal take great care not to damage the ceramic part of the seal.

Have you checked to make sure there is not a 'weep' from the engine gasket between pump and engine?

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  • Posted 315 days ago (08 July 2012 19:23)
southy1981

Joined:

Sep 10

Posts: 49

southy1981 says:

Hi Smidget

I replaced seal number 11 last week but problem is still there, was a genuine Yamaha part as well but when i slid the pump in it took less effort than getting it out, like as though the seal was not beefy enough!!

Racking my brains trying to work out where its coming from, but can only assume that seal number 8 would also stop the oil coming through and i am sure when looking at the Yamaha manual i have that another seal slides into the back of the impellar (where the line is with number one above it).

Would replacing number 5 and 7, and presumably i will have to replace number 11 again?

I am not sure how much it leaks whilst riding as when i get home after an 11 mile commute, on the bottom of the pump is just a drip accumalting ready to drop, it is not leaving a puddle, but i can wipe it with my finger and it is definatly oil

Like i said no oil in water and vice versa, and as my old man always says fluid should stay in the engine.

 

Cheers


Andy

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  • Posted 315 days ago (08 July 2012 19:38)
kcmc

Joined:

Jan 08

Posts: 5279

kcmc says:

Yamaha 250 Majesty 1998

Hi Southy1981

Could be Yamaha has supplyed you with the wrong seal 11?

 

Just a thought,very probably wont be this,but worth a check,the engine breather pipe off the cylinder head isn't kinked or blocked some how causing a build up of pressure,which will cause oil leaks. 

KCMC:tongue: 

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  • Posted 315 days ago (09 July 2012 04:39)
southy1981

Joined:

Sep 10

Posts: 49

southy1981 says:

Hi KCMC

I was hoping you would chime in at some point!! I havent disturbed anything in that area (cylinder head breather pipe etc) well not that i know of, the only time i have was when i checked the valve clearance which needed the tank lifting. Maybe i have jambed something, but as i have to babysit until the wife gets home, i wont be able to get out there.
It is an annoying problem, i cant see that Yamaha sold me the wrong seal as it seated perfectly on the water pump before i slotted it in. Would like Smidget said if oil seal number 7 was buggered, would it let oil into the water (which as i have said, up to this point there is no water in oil and vice versa) as i was under the assumption that the mechanical seal would prevent this?? I am pretty sure that it could be leaking from the tattle hole, i looked at it when i removed the pump, it is there for a reason i believe?

Just want to cover all the bases as if i remove the pump again, i will have to drain all my new coolant and the fresh oil i put in (more money).
Would like to get it sorted all in one go as i have just ordered so DR Pulley slider weights so as i will be in that area i would like to do the whole lot!!

Cheers for the advice so far!!!!


Andy

[This Reply has been modified by the Author]

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  • Posted 314 days ago (09 July 2012 16:00)
smidget

Joined:

Nov 07

Posts: 2050

smidget says:

Hi Andy

Drain oil into clean container, do same with coolant.

Seal 7 would normally allow oil / water to mix, but if the oil is definately coming from the 'tattle' hole this is the only seal which could be the cause. The 'tattle' hole only normally allows coolant to egress indicating a water pump mechanical seal failure.

However if as KCMC suggests there is a positive crankcase pressure then you will have to re-inspect the 'O' ring 11 and it's recess for signs of damage. (Did you fit this dry or did you fit with 'O' ring lubricated so that it was able to spread whilst you were tightening it down?)

Are there any other signs of oil being emitted from the engine via seals or gaskets?

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  • Posted 313 days ago (10 July 2012 09:12)
southy1981

Joined:

Sep 10

Posts: 49

southy1981 says:

Hi smidget

When I installed the o ring I wiped a bit of oil over it so it slid in easily, with regard to tightening it down the o ring (if you look on diagram above) doesn't expand inwards but outwards. Maybe I damaged it when installing it? Originally this is what I thought to be the cause, but am going to pop the tank tonight and check I have not kinked a hose or dislodged anything before I remove anything else. 

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  • Posted 313 days ago (10 July 2012 10:13)
smidget

Joined:

Nov 07

Posts: 2050

smidget says:

Hi Andy

Not having had hands on with one of your machines I am going to make a wild guess after looking at the various diagrams. One in particular caught my eye that being the one marked 'crankcase'.

It depicts two seperate crankcases one forward and one rear, in the forward crankcase it shows an oil seal which is for the crankshaft, this lies above the water pump from what I can determine.

Now my stab in the dark is that it may be this crankshaft seal which has a minor leak at present and it is this which is presenting itself at the 'tattle' hole.

Crankcase diagram, seal 12, on parts list markewd as (25g).

As I say purely a stab in the dark.

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  • Posted 313 days ago (10 July 2012 10:53)
southy1981

Joined:

Sep 10

Posts: 49

southy1981 says:

Hi Smidget

I could be I guess. I will be in that area when I change the rollers so I could check.

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  • Posted 313 days ago (10 July 2012 11:24)

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