Author Topic: Front brake Silicone Grease Source 1970 CB750  (Read 2700 times)

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Offline DaveInTexas

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Front brake Silicone Grease Source 1970 CB750
« on: June 09, 2006, 09:05:47 PM »
We need to use 'the specified grease', later described as a "Silicone Sealing Grease" per p138 of my manual, when reassembling the slave cylinder. 

I was having a hard time finding this and did locate something today.  I post it here to check if you think it is OK, and as a reference for others who might want help finding a (US) source later on.

NAPA "Sil-Glyde" is a small tube, about 5 bucks containing a silicone grease for brake parts -20 to +600F Napa PN 765-1351.



Offline TwoTired

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Re: Front brake Silicone Grease Source 1970 CB750
« Reply #1 on: June 09, 2006, 10:56:31 PM »
No.
That stuff is regular grease with some silicone added.  It will liquify at about 175-200 degrees (one or two hard stops) and flow right into your brake pads and onto your disk.  Personal testing and experience.

What you want is Dow Corning High Vacuum grease.  I know of no substitute.

http://www.2spi.com/catalog/vac/dow.shtml

Cheers,
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline DaveInTexas

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Re: Front brake Silicone Grease Source 1970 CB750
« Reply #2 on: June 10, 2006, 02:58:47 AM »
The Dow Corning temp specs seem quite a bit lower than the NAPA silicone!  I'm no good at converting C to F but the DC will melt at 200C per the link you've posted whereas the NAPA would need 600F to melt.

Are you saying they are 'telling stories' about these temperature limits?

I don't see any petroleum products listed in its MSDS:
http://www.worldpac.com/msds/WP_001.pdf

Thanks


PS this bike place also thinks it is 'the right stuff'
http://www.royalenfieldusa.com/product_info.php?cPath=1_41&products_id=6688&osCsid=d86fa12c19d294baa6ebd35a7bf4d584




No.
That stuff is regular grease with some silicone added.  It will liquify at about 175-200 degrees (one or two hard stops) and flow right into your brake pads and onto your disk.  Personal testing and experience.

What you want is Dow Corning High Vacuum grease.  I know of no substitute.

http://www.2spi.com/catalog/vac/dow.shtml

Cheers,
« Last Edit: June 10, 2006, 03:10:55 AM by DaveInTexas »

Offline TwoTired

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Re: Front brake Silicone Grease Source 1970 CB750
« Reply #3 on: June 10, 2006, 10:34:28 AM »
200 degrees Celsius = 392 degrees Fahrenheit

Well, its a simple test.  Make a little tray out of aluminum foil and put dab of sil-glyde in it.  Then, put it in your oven along with a meat or candy thermometer.  Set the oven to 500 degrees.  Write down the temp and the appearance description in 50 degree increments.
 That's what I did after replacing my sil-glyde soaked brake pads a some years ago.  Maybe they changed the formula since I tested it.
I did the same test with the Dow corning stuff and it was still a gel at 500 degrees (my oven limit). (though it was looking a little glossy ::) )  I remember wondering it the stuff was actually from this planet.

Carefull with specs reading.  A lube break down temp is NOT the same as physical state change.

The spec sheet you linked to, says the stuff is mostly propylene glycol (thickening agent) and Castor oil.  Castor oil is a good high temp lube. "effective from -20°F to 600°F"   But, neither is in a gel state beyond about 200 degrees F.

I'm sure it will lube your disk brake rotor no mater how hard you squeeze the brake lever and never burn off.

Fact is, for the Honda caliper you don't need a lube, you need a water shed that stays in place.

Good luck with your choice!
« Last Edit: June 11, 2006, 12:40:25 AM by TwoTired »
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline andy750

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Re: Front brake Silicone Grease Source 1970 CB750
« Reply #4 on: June 10, 2006, 04:01:52 PM »
Im using the Dow Corning vacum silcon grease on the front caliper of my CB750K4 and I can confirm Lyods overservation - no more brake squeak and after 500 miles its still there.

Cheers
Andy in Boston
Current bikes
1. CB750K4: Long distance bike, 17 countries and counting...2001 - Trans-USA-Mexico, 2003 - European Tour, 2004 - SOHC Easy Rider Trip , 2008 - Adirondack Tour 2-up , 2013 - Tail of the Dragon Tour , 2017: 836 kit install and bottom end rebuild. And rebirth: http://forums.sohc4.net/index.php/topic,173213.msg2029836.html#msg2029836
2. CB750/810cc K2  - road racer with JMR worked head 71 hp
3. Yamaha Tenere T700 2022

Where did you go on your bike today? - http://forums.sohc4.net/index.php?topic=45183.2350

Offline DaveInTexas

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Re: Front brake Silicone Grease Source 1970 CB750
« Reply #5 on: June 11, 2006, 07:43:56 AM »
GOOD info, thanks!  I was planning the heat test, but in the oven would be pushing it, the carbs on the kitchen table drew no fire but grease in the oven might!  I was thinking of trying the bbq, it has a thermometer on it.