Lubricant on water seal?

[[3889]]

I'm planning to fit a new water seal to the raw pump on a Yanmar 3ym30. Any reason NOT to use grease to ease its progress?

 

[pvb]

Ordinary grease might have a tiny risk of degrading rubber, I'd use a smear of silicone grease.

 

[dava]

Silicone spray, get it at any plumbers merchant or DIY place.

 

[VicS]

As above silicone grease/ spray

Glycerine from the kitchen cupboard, washing up liquid, saliva. "Personal lubricant" would be good.

The Service manual says grease. RTM!

Note what the owners manual says about direction of rotation when fitting the impeller

 

[jiris]

As above silicone grease/ spray

Glycerine from the kitchen cupboard, washing up liquid, saliva. "Personal lubricant" would be good.

The Service manual says grease. RTM!

Note what the owners manual says about direction of rotation when fitting the impeller

I wouldn't worry about the rotation direction. The impeller has to cope with thousands of changes of direction during it lifespan - typically when the engine stops and then the remaining compression turns it back half a turn or so. Happens all the time...

 

[VicS]

I wouldn't worry about the rotation direction. The impeller has to cope with thousands of changes of direction during it lifespan - typically when the engine stops and then the remaining compression turns it back half a turn or so. Happens all the time...

May be not but its up to the OP whether to to follow the instructions in the manual or to take notice of what you say. After all what do Yanmar know about it

 

[jiris]

May be not but its up to the OP whether to to follow the instructions in the manual or to take notice of what you say. After all what do Yanmar know about it

If we should be pedantic. I said what I would do, not what what the OP should do. The fact is, I stopped worrying after watching the impeller blades changing bend direction (sometimes even twice) after almost every stopping the engine with the plate removed. Yanmar, coincidentally. I am wondering what Yanmar knows about it too .
The reason I am mentioning this: I was finding frustrating when after a laborious pushing the impeller in twisting it left and right the bloody thing finally slipped in - bent the wrong way. Back to the drawing board... Admittedly, this was before I discovered that little trick with cabletie over the paddles .

 

[RichardS]

I wouldn't worry about the rotation direction. The impeller has to cope with thousands of changes of direction during it lifespan - typically when the engine stops and then the remaining compression turns it back half a turn or so. Happens all the time...

I thought exactly the same as you Jiris. I'm now glad that I didn't pen my thoughts at the time.

Richard

 

[[3889]]

Thank you for the reassurances. I think of PBO as an alternative to reading manuals which are often not to hand. I'm struggling to think of any question ever asked here to which the answer could not be found elsewhere.

 

[Halo]

A key thing with the 3YM30 is not to overtighten the belt. The bearings are easily damaged.

 

[vyv_cox]

I have a pump body and impeller with a long shaft that I can turn by hand, for demonstration purposes. It is surprisingly easy to reverse the blade direction, takes very little effort. That is with a typical impeller for small engines, might perhaps be different for something bigger.