On Thursday 23 October 2014 03:22:11 Gregg Eshelman did opine And Gene did reply: > On 10/22/2014 2:18 PM, jrmitchellj . wrote: > > As an example of what I am talking about, a couple of years ago, I > > had a film scanner, costing new several hundreds of thousand of > > dollars, fail. The service tech came out and stated a box in the > > system had failed, and would cost $6500 + labor to replace. I sent > > him home! > > I pulled the box out of the system, opened it up to find a Pentium 5 > > SBC, and several servo control boards (that I looked up on the > > internet). On close inspection, I found that the fan on the Pentium > > heat sink had failed. I pulled the chip out of the socket, and it > > showed that the magic smoke had leaked out due to excessive heat. I > > found one on Ebay, ordered it, got for less than $7, delivered. > > Installed it, put everything back together, and tested. > > SUCCESS! > > If you want the fan to not fail again, use a drop of silicone oil on > its bearings. Silicone brake fluid is ideal for the job. It's > essentially silicone oil with a touch of purple dye and possibly some > corrosion inhibitors. > > It has much better heat resistance and will not dry out due to > evaporation of VOCs.
That is not something I would recommend Greg, although its not anything I have tried either. The reason I wouldn't try it is, particularly in a sintered bushing bearing, silicone has essentially zero surface tension, and will allow metal to metal contact, accelerating shaft wear considerably. Only if well flooded, and spinning fast enough that those teeny bearings could float on the hydrodynamic oil film, could I see where it might be a good idea. OTOH, when such a dot4 fluid is analyzed, how much of it is actually silicon based. Good question. Anecdote about cheap dot3/4 stuff. 30 years ago, when I was using a CB350F for a chair car in northeastern Kalipornia, I had to add some fluid to the front brake. Took about 3 oz of a fresh half pint of what was supposedly good stuff. Yeah, sure it was, it ate, rotted, swelled and froze every piece of OEM rubber in the system. I wound up replacing the handlebar master cylinder, all the hose down to the caliper, and the caliper which froze the front wheel up solid. I had to stop (it stopped me anyway), get out a screwdriver & hammer to wedge the caliper pistons back away from the disk, then using only the back brakes, went to the bike shop and got the hose and the two kits to rebuild the whole maryann. In those days they would sell you a cylinder kit, now the feds have mandated you have to buy it all new, raising the price by about $400 in 1980 dollars. Moral, if you can smell it, put it back on the shelf & try another brand, there is, or was, lots of dot3 and dot4 stuff on the shelf that would quickly destroy the rest of the system. This one even had a dot-3 on the master cylinder cap! Lasted about 12 hours after adding some cheap dot3/4 stuff. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
