Yanmar 3YM20 raw water pump lip seal

[Ziggy]

In an earlier thread Jim Cate suggested replacing the spring inside the lip seal with an o-ring. I just received a water pump rebuild kit, and the replacement lip seal does not have either a spring or an o-ring. In the original Yanmar lip seal I took out, the spring was either completely rusted away or was never there in the first place. Should I be searching for a right sized o-ring to press into the new lip seal?

[bil56]

lip seals are also available with stainless steel springs

otherwise the replacement of the spring by an O-ring is possible, finding the right size is not easy, quite elastic, not too rigid so as not to wear the lip too quickly or risk marking the shaft

[Wotname]

It sounds like the lip seal has been designed to operate without a garter spring (or garter O ring). If so, leave it as designed. While all the lip seals I have seen do have garter springs, maybe there are newer designs without such springs.

Can you see a grove in the lip seal where a grater spring would sit? If not, leave it be.

[Ziggy]

False alarm--on closer inspection, I see there is a garter spring! By the way, I think it would be damn near impossible to replace it with an o-ring without damaging the seal.

Thank you for the replies!

[jamhass]

There may be (should be) an item number on the seal, as most are not manufactured by the engine/pump/etc company. You should be able to look up (or cross-reference) the item number and find the specs which should ID the spring material. If NOT stainless and in contact with salt water (as opposed to a seal on the oil side) consider replacing with an o-ring. Looks hard, but really isn't.

[Rapanui]

If you change the lip seal every year when you replace the impeller, then the pump should not need refurbishing for many years. Buy a handful of generic lip seals with stainless gaiter springs for peanuts. Remove the impeller, hook out the seal and press in new. A dental pick makes it easy peasy. Use minimum belt tension to reduce side load on shaft.
Once the seal starts to leak, it only a matter of time before the bearings fail, so replacing them early prevents that.

[Uncle Bob]

I go to a bearing supply business with the old seal in hand and explain that it is for a water pump, they grab a new seal off the shelf, pluck out the spring with a dental pick and fit the correct o ring and then ask is that all as they have a $10.00 minimum charge, perhaps I would like a spare? Works for me.

[Jim Cate]

Originally Posted by Uncle Bob

I go to a bearing supply business with the old seal in hand and explain that it is for a water pump, they grab a new seal off the shelf, pluck out the spring with a dental pick and fit the correct o ring and then ask is that all as they have a $10.00 minimum charge, perhaps I would like a spare? Works for me.

My experience also, UB. Don't know what all the fuss is about!

Jim

[Ziggy]

Originally Posted by Uncle Bob

I go to a bearing supply business with the old seal in hand and explain that it is for a water pump, they grab a new seal off the shelf, pluck out the spring with a dental pick and fit the correct o ring and then ask is that all as they have a $10.00 minimum charge, perhaps I would like a spare? Works for me.

Nice people those Aussies. I'm not sure I could find a neighborhood shop like that here.


My original lip seal lasted 14 years before it started to leak. But periodic replacement sounds like good advice.

[sailingchiro]

Yes, I just rebuilt two of my water pumps (both spares). Bought the bearings about $1.50 a piece and replaced the seals with double lipped seals for about $4 each. I purchased enough bearings and seals to last a lifetime. This is for a Johnson pump from Beta.