Which grease when changing impeller ?

[capricorn]

Changed my engine impeller a couple of weekends ago.

I gave the new impeller and pump housing a good smear with the same water resistant grease that I use in my stern gland greaser.

All ok after 10 hours motoring since but becoming somewhat concerned about the grease potentially destroying the rubber and causing premature failure of the impeller.

Did I make a mistake ?

 

[duncan]

my engine manual simply referes to 'grease' for this job, but is a lot more specific in other areas!

this, plus the huge price for these items, leaves me concluding that you can use silicone grease, teflon grease, very sticky grease, gungy grease.....................all without risk to the impellor itself

 

[Malish]

I would use a silicone grease for this job. I do think that you are possibly a little over-concerned about the destruction of the rubber - the majority of the grease will be rapidly expelled from the pump via water flow, probably leaving little more than a thin veneer on the metal face. The main reason I apply grease is to provide a little lubrication on intial start-up after replacing the impeller while the pump is still running dry.

 

[tcm]

agreed. Silicone grease won't attack the rubber, though it's marginal in that environemtnt and althoughh the petroleum-based grease can affect rubber any effect takes ages and wd need the grease to be trapped near the rubber , which it isn't: the finest smear will remain, most importantly on the shaft i spose to get the thing out again sometime. So not to worry imho.

 

[essexboy]

I use Vaselene, it doesnt rot rubber ( I hope !)

 

[FullCircle]

Did you have to bring the tone of the thread down?

 

[Stellina]

Just bought a spare impellor from Volvo and was impressed it came with a small tube of lubricant. It was glycerol.

 

[Dave_Seager]

Although I have used various types of grease over the years, Volvo advise against this and supply a sachet of lubricant with their impellors.

I always remove my impellors for the winter and did not have any spare glycerine when refitting them this spring. Soft soap was a recommended alternative so I raided the heads and used liquid soap. This worked very well and comes in a convenient dispenser too. It should disperse very easily once the water starts to flow and provides an interesting perfume in the engine room!

 

[Landale]

I would agree, silicone grease is faily inert but not that inert and likely to hang around the pump housing. Petroleum based greases with sea water and metal appear to react well together. Glycerol (Glycerine) which is what Volvo supply just disolves in the seawater and is washed away.

cheers

 

[30boat]

I never use grease.Last time I did the impeller desintegrated within a month.Maybe I was unlucky.Vaseline is perfefctly safe and works just as well.

 

[John_Clarke]

Johnson Pump's website agrees with this and states:
“Use only glycerine to prevent damage from dry running at start up. Run engine after installation. Do not use petroleum products to lubricate the inside of the pump.”
You can buy a bottle of glycerine from Boots the chemist. It is water soluble.
It also makes it very easy to rotate the impeller into the housing.

 

[LeonF]

Typically British attitude that anything to do with sex is lowering the tone !! When I posted about lubricating hoses and KY was suggested I thought it was a wind up...but it certainly did the trick... /forums/images/graemlins/smile.gif

 

[nedmin]

used silicon grease for years,no probs.

 

[Poignard]

A smear of washing up liquid.

 

[bumblefish]

Ecover?