Replacing water pump impeller

[tip]

I'm replacing the impeller on my 8hp outboard. What should I lubricate the new impeller with?

Don Casey says petroleum jelly, but what do you guys use? I couldn't find any answers searching.

[Gene T]

I use Teflon grease on all things marine. Has worked great on impellers.

Gene

[75R20]

I used petroleum jelly on the impeller and housing, and on the various seals that needed to be lubed to be reinstalled. I believe that my Honda factory manual said to use it also.
Best of luck
Kary
S/V Mariah
#49080

[sailingdog]

I'd recommend using a silicone grease rather than petroleum jelly. Petroleum products tend to attack many plastic and rubber compounds.

[tip]

silicone grease it is...I have plenty of that. Thanks guys!

[75R20]

Originally Posted by sailingdog

I'd recommend using a silicone grease rather than petroleum jelly. Petroleum products tend to attack many plastic and rubber compounds.

While I agree with this statement in a general sense, most all things in the automotive/marine arena are using synthetic rubber compounds and the petroleum jelly will not harm that. I've never seen a plastic harmed yet, but anything is possible.
Example; All automatic transmission seals are lubed prior to assembly with Vasaline/petroleum jelly. Doesn't matter if it's a Yugo or an Allison HD truck transmission. Industry standard.
Best of Luck
Kary
S/V MAriah
#49080

[sailingdog]

I'd point out that transmission seals are generally made of compounds that are not damaged by petroleum products, as they are constantly exposed to transmission fluid, which is one.

Water pump impellers are often made of very different compounds, and you're basically comparing apples to oranges.

Originally Posted by 75R20

While I agree with this statement in a general sense, most all things in the automotive/marine arena are using synthetic rubber compounds and the petroleum jelly will not harm that. I've never seen a plastic harmed yet, but anything is possible.
Example; All automatic transmission seals are lubed prior to assembly with Vasaline/petroleum jelly. Doesn't matter if it's a Yugo or an Allison HD truck transmission. Industry standard.
Best of Luck
Kary
S/V MAriah
#49080

[sailingdog]

BTW, from the Johnson Pumps Impeller brochure:

Warning! Do not use any petroleum-based products to lubricate the inside of the pump. Only use Johnson Pump Lubrication. Other products can damage the impeller, which will damage the pump and lead to engine failure. Do not run the impeller without water or lubricant, this can cause engine failure or a fire.

[sailingdog]

I'd point out that Don Casey also says you should let sealants cure and then finish snugging the bolts down, which is one of the stupidest and most costly things you can do when bedding deck hardware IMHO. You're really better off countersinking the fastener holes slightly and then torquing the bolts all the way down the first time, before it cures.