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Freezing Bearings/ Condensation


mossman's Avatar
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08-18-16, 10:15 AM   #1  
Freezing Bearings/ Condensation

I'm rebuilding the bottom end of a CRF250R dirt bike and am currently freezing the crank and transmission bearings. Do I need to be concerned with condensation after installing the bearings? It's humid here in VA and there will definitely be condensation on the bearings after I install them. I thought of perhaps spraying them down with brake kleen after they are installed, but don't want to flush out the factory lubrication. Or maybe that isn't a big deal because they will eventually be flooded with oil anyhow? Is the factory grease for protecting the bearings upon initial break-in?

 
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08-18-16, 04:59 PM   #2  
Condensation isn't a problem. If you have a lot of droplets inside the crankcase rinse them out with WD 40, then run the engine for 10 to fifteen minutes after you get it going, then change the oil. Don't use Brake Kleen in there.

The grease on the bearings protect it during shipping and storage against moisture and bearing against race damage.

 
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08-18-16, 06:28 PM   #3  
Just put the bearings in. Moisture wasn't a problem whatsoever. I'm sure installing them in a 65 degree basement helped.

 
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08-19-16, 01:38 PM   #4  
Should I go ahead and flush out the factory grease with WD-40 now that the bearings are installed? There's already going to be cocktail of greases and oils (moly paste, moly grease, oil, loctite, etc) in the crankcase upon initial break-in until I do the first oil change, so I'd like to minimize as much as I can.

 
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08-19-16, 04:20 PM   #5  
The factory grease will blend with the motor oil upon the initial running. The reason you would use the WD40 is it would collect the moisture if there was a lot of that and still provide lubrication to everything on first start up

Since you didn't have much, don't worry about the WD40. Just let it all clean itself out with the first oil change. I would run it for about fifteen minutes or so - long enough to get it warmed up good. Then change it.

 
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08-19-16, 07:43 PM   #6  
Okay. I'll leave it then. Thanks.

 
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