Servicing the engine raw water pump

[sheyes]

I am servicing the Jabsco raw water pump on my Beta engine. There are two seals on the shaft which are there to keep water and oil separate while the pump does its job. Both seals are the same. They are like (black) polo mints which are almost flat on one side and the other side has a deep slit in it which goes right the way round.

I had been told that the slit side should point toward the liquid it is protecting the bearing from which should mean that the seal nearest the impellor should have its slit side pointing out toward the impellor. When I stripped the pump down I found that the seals were put on in the opposite way than expected.

The question is which way round on the shaft should the seals go (or doesn’t it matter)?

Steve

 

[KenMcCulloch]

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I had been told that the slit side should point toward the liquid it is protecting the bearing from which should mean that the seal nearest the impellor should have its slit side pointing out toward the impellor. When I stripped the pump down I found that the seals were put on in the opposite way than expected.


[/ QUOTE ]
Dear Steve
The advice you have been given seems correct. Any pump I have had anything to do with has had the seals arranged in the way your adviser describes. If you have found the seals with the 'open' sides together that sounds like mis-assemby to me.

 

[Guest]

Try:

http://www.alliedseawindii.org/kbase/equipment/engine/pumps/jabsco-5320-0011/jabsco-5320-0011.html

Hard to follow. But "lips" are facing towards impellor.

However, the inner oil seal seems to be trying to keep water off the bearings. I assume the bearings are sealed for life types. Some have bearings that are part of the engine oil system. Depends were the seals are in relation to bearings.

Remember the slinger. Helps to keep water and oil separate when a leak does occur. Especially during early bearing failure times. It slings the oil or water out through the gap in the casing. Normally just an O ring.

 

[kiwikol]

Steve- Sound like ‘lip seals’ – as used in vehicle wheels hubs bearings for example. I also use them as the prop shaft seal – work really well and no leaks at all ! The ‘lip’ side faces the water in an impeller situation, as you have been correctly told. A bit of advice though – in the slit you will find a round spring. This is probably just a ferrous steel spring and in which case you should remove it and replace with a rubber ‘O’ ring. The steel will rust very quickly in salt water! Believe me – I’ve experienced it in a new (Yanmar !!) engine!! Oh yes, the slinger – it should be a proper deflector with a curved sectional shape – the concave side faces TOWARDS the impeller.

 

[rogerthebodger]

You can get lip seals with stainless steel and/or copper springs for use when the seals are to be used in water pumps. When oil is sealed normal spring steel is OK.

Go to a bearing / seal supplier and ask, if they dont know go some where else