Author Topic: How to change grease on sealed bearings?  (Read 391 times)

Offline PekkaNF

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How to change grease on sealed bearings?
« on: June 29, 2017, 06:47:21 AM »
Situation is like this: I can buy just the right bearing, but it has wrong lubricant and wrong amount of it. I.E. I want low friction sealed bearing with very little high rpm grease.

Industry would just spesify the bearing, seal and grease and order a pallet load of them.

In priciple it is easy: Pop out the seal, wash and a dab of correct lubricant. Wrong. All has to be very clean and I have tried some mildly high speed (like hand routers) stuff and the rubber seal never goes back as good as original. It might look fine, but the lip rubs and generates heat.

This how-to-not:
https://youtu.be/Np5dcns64Fs

Although this is interesting:
https://youtu.be/tO3BbwkMdFI

Starting from new design I could use one sided seal and arrange sealing othervise or put two back to back.

Offline russ57

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Re: How to change grease on sealed bearings?
« Reply #1 on: June 29, 2017, 08:45:59 AM »
 Could you use a hypodermic needle with some solvent to flush the old grease out? Through the rubber seal. Id think it would self-heal sufficiently. Then either inject the new lubricant, or maybe try that vacuum approach.. Hard to control the amount that way though.
Russ

-russ


Offline David Jupp

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Re: How to change grease on sealed bearings?
« Reply #2 on: June 30, 2017, 09:19:12 AM »

Offline PekkaNF

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Re: How to change grease on sealed bearings?
« Reply #3 on: June 30, 2017, 04:14:15 PM »
Actually I have heard of that sort of services, that looks pretty specialized. I have heard some cases of a pallet of bearings nearing self life filled with fresh grease and sold. Don't knew if they went on agricultural or consumer stuff or just sold wheere ever.

Anyways, have been working with Ford focus 2006 pissing off cooloant from core plugs - at cylinder head between sparkplugs.

I might need to test this one soon or maybe I get lucky and find the appropriate bearing from the self.

Pekka

Offline awemawson

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Re: How to change grease on sealed bearings?
« Reply #4 on: June 30, 2017, 04:19:28 PM »
I've never tried, but is it not possible to ease the rubber seals out of a bearing and then re-fit them? I would have thought that is was  :scratch:

In which case just flush the bearing with the solvent of your choice (I'd use a WD40  or brake cleaner spray) then re-lube as needed
Andrew Mawson
East Sussex

Offline awemawson

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Re: How to change grease on sealed bearings?
« Reply #5 on: June 30, 2017, 04:24:44 PM »
Here you go, looks easy enough:

<a href="http://www.youtube.com/watch?v=gCXMICrjKd4" target="_blank">http://www.youtube.com/watch?v=gCXMICrjKd4</a>

Andrew Mawson
East Sussex

Offline mattinker

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Re: How to change grease on sealed bearings?
« Reply #6 on: June 30, 2017, 04:34:22 PM »
I have done this very frequently over the last thirty years. I discover how little grease there were in bearings with seals when I worked with an auto electrician in Toulouse. My colleague systematically took the seal of alternator bearings and repacked them.

Never had any trouble doing this!

Regards, Matthew

Offline PekkaNF

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Re: How to change grease on sealed bearings?
« Reply #7 on: June 30, 2017, 07:35:06 PM »
RS sealings come out and are easily pressed back easy too. However I only had good degree of success on low rpm application. Whenever I tried this to low friction type seal it did not work that well. They look the same than RS seal, but often are harder material and they should nor rub. Bit like plastic version of Z (dust seal). Got some one sided RS and Z bearing on last batch, have some time to experiment.

Pekka

Offline edward

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Re: How to change grease on sealed bearings?
« Reply #8 on: July 03, 2017, 09:30:53 AM »
The 2RS seals on my bike bearings come out no probs for a quick flush and a squirt of new grease. I use a scalpel to pop them out but they are only small-ish ones like 6000, 6001.

Offline sparky961

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Re: How to change grease on sealed bearings?
« Reply #9 on: July 03, 2017, 10:10:42 AM »
Have you checked if you can get brand new replacement seals? You might have better luck getting a new one back into place.