Proper lubrication?

FlyingDutchman

FlyingDutchman

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In a month or so it is time again to put a new impeller in the water pump.
I always buy the VP original impeller kit that comes complete wit the gasket and some lubricant. The lubricant is very thin and the impeller seems to repel the stuff, it does not smear on and does not stick like grease.
Question is: Should I use the VP stuff or go for something else like petroleum jelly or silicone grease? A grease like type of libricant could also provide an emergency libricant in case I should forget to open the sea water cock (don't ask!)?
 
If you buy the VP replacement and it's supplied with some lubricant by VP I cant see that anyone can advise you other than to use that which is supplied.

The impeller may not be compatible with petroleum jelly. Probably the stuff supplied is water based so maybe if you just feel a bit more is required use KY or other brand of personal lubricant.

Don't forget to open the sea-cock ... some people hang the keys on it when its closed.
 
My Volvo Penta Operators Manual (D1 D2) says

'lubricate the pump housing and the inside of the cover with a little glycerin.
IMPORTANT! The impeller will be damaged if other types of lubricant than glycerin is used'

Glycerin is available from the pharmacy in little bottles and has a diversity of lubricating function on the label but nothing about impellers.
 
IIRC the supplied lubricant is glycerine but I'm not sure why.

Presumably, as VicS suggests, an oil based product might be harmful to the rubber.

Apparently KY Jelly is glycerine based. ;)
 
Quandary said:
My Volvo Penta Operators Manual (D1 D2) says

'lubricate the pump housing and the inside of the cover with a little glycerin.
IMPORTANT! The impeller will be damaged if other types of lubricant than glycerin is used'

Glycerin is available from the pharmacy in little bottles and has a diversity of lubricating function on the label but nothing about impellers.
Click to expand...

You must type quicker than me :)
 
I always use lots of waterproof grease on the splined shaft and wipe a a good blob al around the inside of the pump body. I always take the impellors out every autumn and let them relax. On my last boat the impellors were still in good condition after 7 years.
 
Many thanks for all your thoughts.
After reading the posts I think that the stuff supplied with the impeller is glycerine.
It has about the thickness of fairy liquid and is colourless. I feels 'greasy' but it does not stick to the rubber of the impeller. it lies on top of the surface in small drops. On the housing it does spread and stick. I think I will just continue to use it.

I always put in a new impeller at the start of the season for peace of mind but I have wondered if this is really necessary. We do about 70 / 80 hours per year on inland waters.
I don't bother to take out the impeller after the season but last spring I noticed that when I took out the impeller the blades were badly bent in one direction. I showed it to SWMBO and said: This is why we need a new impeller every year and mounted the new one! After an hour or so she showed it to me and said: You can put it back, all the blades are ok now! She was right, after removal the blades regained their original position and a closer examination showed no hairline cracks or wear on the blade tips or the front / aft end of the impeller.
 
FlyingDutchman said:
I always put in a new impeller at the start of the season for peace of mind but I have wondered if this is really necessary. We do about 70 / 80 hours per year on inland waters.
Click to expand...

Our engine does about the same annual hours as yours. I do remove the impeller each winter and inspect it closely. It will shortly go back in for the fifth year. I use a silicone grease for re-assembly which seems to have no effect on the rubber of the impeller. If I were you I would start re-cycling all your old impellers and save youself a few beer tokens for the next few years.
 
Hi All,
Washing up liquid is fine for installing impellers and works a treat, and as long as the pumps are not run dry and cooked during the season they should last for a few years if they are removed each winter (if poss),
however when left in, it is the long period of inactivity which is the killer, as the vanes lie tightly curved on one side and slightly more relaxed on the other and when they are left like this for long periods they tend to lose their ability to recover properly and so do not pump efficiently in the spring.
We recommend that they are swapped every other season as a precaution anyway, and if the old ones recover well after they have been out for some time, carry them as spares.
The other issue to consider is that when they do fail catastrophically they usually send all the vanes/blades into the heat exchanger /oil cooler/intercooler or whatever else is next after the pump. :)

Phil
 
FlyingDutchman said:
In a month or so it is time again to put a new impeller in the water pump.
I always buy the VP original impeller kit that comes complete wit the gasket and some lubricant. The lubricant is very thin and the impeller seems to repel the stuff, it does not smear on and does not stick like grease.
Question is: Should I use the VP stuff or go for something else like petroleum jelly or silicone grease? A grease like type of libricant could also provide an emergency libricant in case I should forget to open the sea water cock (don't ask!)?
Click to expand...

The lubricant is glycerin.

The Volvo impeller is almost certainly made by Johnson Pumps - buying their replacement impellers will save you a lot of money.

In the days when I had to take off the pump to get at the faceplate to change the impeller, I always used to carry a spare pump.
With the new motor I only change the impeller when it fails. This seems to happen at about 500 hrs service - so for most people changing the raw-water impeller annually is probably gilding the lily, but bringing joy to the hearts of manufacturers, distributors and agents.
 
alahol2 said:
Our engine does about the same annual hours as yours. I do remove the impeller each winter and inspect it closely. It will shortly go back in for the fifth year. I use a silicone grease for re-assembly which seems to have no effect on the rubber of the impeller. If I were you I would start re-cycling all your old impellers and save youself a few beer tokens for the next few years.
Click to expand...

You guys are brave! It's not so much the problem of a breakdown as what happens when a bit breaks off an impellor and vanishes into the waterways, maybe blocking a passage in the cylinder head on a Raw water engine or wedging inside the heat exchanger on a fresh water cooled one. Heads off, exchanger stripped etc all to save £20 pa.
 
Bosun Higgs said:
You guys are brave! It's not so much the problem of a breakdown as what happens when a bit breaks off an impellor and vanishes into the waterways, maybe blocking a passage in the cylinder head on a Raw water engine or wedging inside the heat exchanger on a fresh water cooled one. Heads off, exchanger stripped etc all to save £20 pa.
Click to expand...

If replacing with a new one was guaranteed to put reliability back to 100% for the next year, I would agree with you. Reality is that new ones can fail very early in their lives. Ever heard of the bathtub curve? It's a plot of the failure rate of a vast number of engineering components. Many fail early in their lives, many others keep going for a long time, eventually all fail. Hence the curve. See an example in wiki

So there is a lot to be said for keeping running a used one, as the chances are that it will last for some time if it has no cracks. I agree with Charles, 500 hours is a reasonable guide for a good one but I have had some fail in 20.
 
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