Topic: the absolute finalword on brake assy lube

[grumpy]

I've read & reread all the 750 brake caliper rebuild posts I could find.
I have the Dow high temp silicon paste. Now I need the assembly lube.

Is this thee stuff?

3M™ Brake Lube/Anti-Seize, 08945

What's so special about this particular stuff?
The MSDS says its just copper & petro-based grease. How is this stuff better than any other anti-seize?
How do you use it when rebuilding the caliper? I read TT's post in the FAQs but I don't really understand why this stuff should go inside the caliper. "Coat the inside of the caliper groove, wall, seal, and piston with the Brake Parts Assembly Lube." Seems to me that copper particulate would be a baaaaaad thing to have circulating in the brake fluid.

 

[MRieck]

I've read & reread all the 750 brake caliper rebuild posts I could find.
I have the Dow high temp silicon paste. Now I need the assembly lube.

Is this thee stuff?

3M™ Brake Lube/Anti-Seize, 08945

What's so special about this particular stuff?
The MSDS says its just copper & petro-based grease. How is this stuff better than any other anti-seize?
How do you use it when rebuilding the caliper? I read TT's post in the FAQs but I don't really understand why this stuff should go inside the caliper. "Coat the inside of the caliper groove, wall, seal, and piston with the Brake Parts Assembly Lube." Seems to me that copper particulate would be a baaaaaad thing to have circulating in the brake fluid.

 

You should only be using new brake fluid to lube the piston and seals

[mark]

3M Anti-Seize...... NOT the stuff for caliper assembly. If you thought the copper dust was bad, wait 'til you see what the petroleum part does to rubber.

great stuff for exhaust bolts and such.

Brake assembly lube is normally a clearish fluid that will mix with brake fluid BUT unlike brake fluid does not absorb moisture from the air. It is normally used when the rebuilt part is to be stored for a time before being installed.


Wet the parts with new clean brake fluid, install piston in caliper, apply Dow grease as directed, install caliper and ride.


Happy trails.

[TwoTired]

That 3M stuff is NOT brake parts assembly lube for contact with brake fluid.  The stuff you are showing is for external parts like pivot/slide pins on automotive disk brakes.

I have two bottles of the brake parts assembly lube. The oldest (30 years?) is Mckay brand brake assembly lube.  The other is Raybestos brand brake assembly fluid.  Looks and feels like the same stuff from either brand.

http://www.autoparts2020.com/rsdev/part_detail.jsp?PART_HDR_ID=40378

[grumpy]

You should only be using new brake fluid to lube the piston and seals

That's what I always thought but the several people here say absolutely not to...

3M Anti-Seize...... NOT the stuff for caliper assembly. If you thought the copper dust was bad, wait 'til you see what the petroleum part does to rubber.

yeah - I couldn't believe that was the right stuff

[grumpy]

The other is Raybestos brand brake assembly fluid.  Looks and feels like the same stuff from either brand.

http://www.autoparts2020.com/rsdev/part_detail.jsp?PART_HDR_ID=40378

Have you seen that stuff for sale around here?

I wonder if Road Rider will order it...?

[TwoTired]

You lube the caliper seal with the assembly lube.
The caliper seal divides the DOT3 area with the outside atmosphere.  Whatever you lube the seal with, it must be compatible with DOT3.
If you use DOT 3 to lube the seal, some of it is then outside the seal in contact with atmosphere.
DOT 3 will pull water out of the atmosphere and place it in contact with the metal parts that will then begin to corrode.
Brake parts assembly lube does NOT attract moisture from the atmosphere.  In fact, it acts as a barrier to prevent moisture from contacting the metal parts of the caliper.
Brake parts assembly lube blends easily with DOT3 on the inside of the caliper.

You decide which is the correct lubricant for the application.

[lowmileage]

  Ok, don't flame me on this 

No place near me has this stuff (Assembly lube).  I guess I could order it over  the net but I'm getting the new caliper seal tomorrow and I'd really like (at this point) to get everything buttoned up to ride this weekend.  So here goes  , what's the downside to using  a quick wipe of Silicone brake fluid on the seal?  I know it doesn't "mix" with Dot 3/4 but I'm only talking a quick wipe. 

[Duke McDukiedook]

Use the Dot 3 brake fluid if you are in a big hurry.
It would be way better than mixing silicone and DOT 3.

[TwoTired]

Yes, if you refuse to use the correct fluid for the task, then just use the same fluid being used in the system.

I don't suppose you plan to protect the piston and cylinder exposed to the elements with the Dow Corning silicone grease, being as you're in a hurry to finish the job right or wrong.

There's the old saying, "A job worth doing is worth doing twice!"


 

[lowmileage]

  Now, now - I asked not to be flamed  .  I do, repeat  , I do intend to use the Dow Silicone stuff.  In fact I have a tube of the precious goo already.    I guess I'll have to find the Assembly lube to get back in everyone's good graces 

[ttr400]

As per MRieck, I only use new brake fluid to lube the internal brake parts. Take a look at a late model sport bike manual............".Warning do not use any solvents to lube internal brake parts.......only use new brake fluid".

Kevin

[razor02097]

Now, now - I asked not to be flamed  .  I do, repeat  , I do intend to use the Dow Silicone stuff.  In fact I have a tube of the precious goo already.    I guess I'll have to find the Assembly lube to get back in everyone's good graces 

You shouldn't have to do anything... Just ride and enjoy it for now.  When you find it and get some time; go ahead and pull it apart and use assembly lube.

[TwoTired]

Now, now - I asked not to be flamed  . 

That was a flame?

Jeez, I guess I forgot the smilies, I'll go fix it...

[lowmileage]

Just kiddin' a bit with ya' 

[Achmed]

I'm reviving this "absolute final word" thread because I didn't realize I need some special assembly lube to reassemble my caliper. My 76 750F sat pretty much all last year and the caliper started binding again when I got the bike out this spring. I have done this job within the last couple years and I live in a very dry climate. Upon taking it apart the outside circumference of the pad has lots of little amber crystals and various sludge/corrosion.

The grease I used between the pad and cylinder looks like it did its job, but I don't think I used enough. The cylinder has no evidence of corrosion, so I think it was just the pad hanging up on the caliper body. But now I'm thinking maybe the master cylinder isn't letting fluid back into it. I don't know enough about master cylinders to know how probable that could be.

Anyway, I started reading up on this assembly lube and my auto parts stores don't have it. Let's pretend I'm using the Dow Corning grease between the pad and piston. Couldn't I also use it for on the piston, all the way down to the outside of the seal? What are the odds any of it could get back into the brake fluid? It seems low to me as the brake fluid is pressurized.

Also here is an article discussing brake fluids and their compatibility:

http://www.buckeyetriumphs.org/technical/Brakes/Fluid/Fluid.htm

The author doesn't seem too concerned about adverse effects from mixing silicone based fluids with Dot 3, although he acknowledges they will not mix. And I read somewhere else someone claim that assembly fluid is just dielectric grease (silicone based).

Is it really a huge no-no to use silicone based lubricants to assemble calipers? Realistically it seems only a tiny bit could get into the (Dot 3) brake fluid.

I know there are several old threads on this so I didn't want to start a whole new one.

Thanks for your opinions.

[TwoTired]

Part of the problem with converting back to DOT3 from silicone BF, is that you can't really get all the silicone out.  Silicone doesn't combine with any solvent.  It puddles in a layer at the bottom just above any water collected, and helps make the lever spongy.

The silicone grease should stay on the outside of the brake fluid vessel where it can shed water away from exposed metal. (It doesn't combine with water, either.)

The correct assembly fluid is NOT silicone based. Brake assembly lube is a synthetic base (MSDS says Polyether Polyol), that won't react adversely with DOT3 brake fluid.
http://forums.sohc4.net/index.php?topic=57772.msg625897#msg625897

[Kevin]

Thank you to all that have contributed to this thread it has been very helpful.
It would be really super duper helpful if this thread and the other thread were combined and condensed and placed into the tips and tricks section.
Thanks again for the information, as you all know, I need all the help I can get

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