Topic: High Vacuum grease on calliper parts?

[orange550]

So I've read most of the threads and FAQ on front brake issues / rebuilding. And it all makes sense... but I just have this nagging question.

I understand to put the Dow corning high vaccum grease on all metal surfaces outside of the piston seal, back of pad, etc. But can you also put a tiny amount on the side of the metal backing of the moving pad so that it slides well agaisnt the inside wall of the outboard calliper? It seems that my pad can get easily stuck there if it gets ever-so-slightly angled / crooked in the calliper housing. I know once it's in place, it will only move a very small amount and won't really have a chance to get crooked, but still...

And really, here's the more important question: regardless of applying it to the side of the metal pad backing, how do you make sure that even grease on the back of the pad/ front of piston doesn't migrate out to the actual brake pad surface? Are you reaally just going by faith that you're not putting too much. I understand that you put only a very thin coat, but even then, does it really never somehow migrate out to the pad? Does it sort of 'set-up' or dry and that keeps it in place.

Anytime I'm putting grease on brake components, I get worried (I just greased the cam shaft on the rear drum, and was stressed about getting enough, but not too much)

Thanks!

[TwoTired]

1 - You only need a thin film coating on the parts.  It's not so much for lubrication, but used as a film barrier to separate the metal from water and oxidation stimulants.  Water will not dilute the correct silicone grease.
2 - The correct silicone grease does not weep, seep, or migrate from where it is placed until temps get somewhere above 500F. ( I did an oven test.  It just glared back at me through the window to the limits of my oven.  I think I heard it defiantly say: Is that all you got?") 

The brake pad/puck should be dry fit into the caliper before assembly to insure it will insert and fall out of the caliper with gravity.  If it does that, then it should never have an issue with binding.

Cheers,

[SohRon]

From the Honda Shop Manual:

[orange550]

So now I just gotta make sure I find the proper grease, and make it a thin coating.

Wow, the manual looks pretty clear to grease the sides of the pads.

[TwoTired]

You just have to coat any exposed raw metal.

[RAFster122s]

What's the difference between the high vacumn Dow silicone grease for the caliper and the CRC caliper grease available from the auto parts stores (Autozone, NAPA, O'reilly's, etc.) ??
Thanks in advance for your help clarifying this!

[TwoTired]

What's the difference between the high vacumn Dow silicone grease for the caliper and the CRC caliper grease available from the auto parts stores (Autozone, NAPA, O'reilly's, etc.) ??
Thanks in advance for your help clarifying this!

I looked it up and it says it is  Polyalphaolephin & Pentaerythritol Esters w/ fumed silica.  Almost certain this is petroleum based.   I would expect this to weep or creep into the friction pads, when used in the SOHC4 application as the pads are adjacent to where it is applied.  Most automotive calipers have physical separation between where the lube goes and where the friction pads are.
You could test it.  Put it in a little cup made from aluminum foil and place it in the oven.  See what it does at elevated temperatures.  If it doesn't look and behave the same at high temps as it does at room temp, it isn't suitable for the SOHC4 caliper.

Dow silicone grease is pure silicone.

[bollingball]

Is this what we need ?

Ken


http://www.ellsworth.com/

[TwoTired]

Is this what we need ?

Ken


http://www.ellsworth.com/

From that site, this is what I tested and know works, and I think what Honda used originally.
http://www.ellsworth.com/dow-corning-high-vacuum-grease-150g-tube/

[bollingball]

Wrong page I think this is it

http://www.ellsworth.com/product-list/dow-corning/Grease/7208/7193/

[TwoTired]

Wrong page I think this is it

http://www.ellsworth.com/product-list/dow-corning/Grease/7208/7193/

That links to 10 pages.  The last page has the correct grease.

[bollingball]

I don"t know why it does that I go to page 10 hit edit copy then when I paste it goes back to page 1??
That little tube should do several bikes.

Ken

[BobbyR]

This is what he was talking about http://www.ebay.com/itm/2-DOW-CORNING-HIGH-VACUUM-GREASE-5-3OZ-new-/260968144644?_trksid=p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D21%26pmod%3D160664168175%26ps%3D54

[MoTo-BunnY]

Here is a picture of the Dow Corning High-Vacuum grease-accept NO substitutes!!!

Seriously, don't even think about using anything else found at automotive parts stores. They may even basically lie to you and tell you whatever they have will work (like they did to me) but it won't! If you saw the greasy mess my front brake was because the previous owner used cheap stuff, you would know what I am saying. (the pads themselves were very well lubed even from grease running down on them....niiiiiiice!)

This stuff is a bit spendy but it is very handy with a variety of things. I used a thin sheen around my locks when I replaced them to prevent corrosion and keep water out. It's great stuff. You can find it sometimes on feeBay cheap when sellers re-sell some with "expired" dates on it (sometimes only a few months expired) and I highly doubt there are any problems using this "expired" grease.

[h2yamyk]

I just found 1 oz mini jars of the stuff on ebay.  I've attached a screen shot so you know how to search for it.  10 bucks shipped.

[madmtnmotors]

What's anyone's take on "Red Rubber Grease"? Described here:

http://www.ebay.com/itm/160817833934?item=160817833934&viewitem=&sspagename=ADME:L:OU:US:3160&vxp=mtr

Sounds like it's made just for this.

[TwoTired]

What's anyone's take on "Red Rubber Grease"? Described here:

http://www.ebay.com/itm/160817833934?item=160817833934&viewitem=&sspagename=ADME:L:OU:US:3160&vxp=mtr

Can't find MSDS.
Can't find manufacturer data.
No chemical base specified.
No test data specified.

Do your own test in an oven, to see how it behaves under high temps.  Let us know if it was worth the effort, and a better deal than the known certain product; Dow Corning HVG.

Sounds like it's made just for this.

Advertising 101:  Make your product appeal to the widest possible audience.  Vague is better than precise.  Don't give any info to base a rejection  upon.

I'm skeptical. 

Cheers,

[crazypj]

Don't know if it's he same stuff but I used to use a lot of the 'red rubber grease' back in the day (looks like it in pic)
 Local autoparts store only carried it in tiny 'single application' sachets which was actually plenty for pair of Honda swinging calipers (or one 4 pot caliper)
 It did prevent corrosion under piston seal, I rarely saw bikes back for brakes to be re-done (they use a LOT of salt on the roads in Britain and people do tent to ride year round)

[madmtnmotors]

What's anyone's take on "Red Rubber Grease"? Described here:

http://www.ebay.com/itm/160817833934?item=160817833934&viewitem=&sspagename=ADME:L:OU:US:3160&vxp=mtr

Sounds like it's made just for this.

Found some MSDS from other manufacturers of the same product description ("Red Rubber Grease") that only rate it up to 120C to 140C so the Dow High Vacuum Grease would probably be the ticket for the grease points on the pad itself (as noted in the manual) while the "Red Rubber Grease" would probably be fine for lubricating the seal and maybe the piston bore, by which I mean a VERY THIN wipe inside the piston bore and seal surface. But then, the Dow High Vacuum Grease would likely serve both purposes, thus requiring only one product? 

[TwoTired]

There are multiple threads about this same topic:

http://forums.sohc4.net/index.php?topic=56544.msg610718#msg610718
  Lets' review.
There are four products needed to restore a caliper.
1. Brake cleaner
2. Brake parts assembly lube for the caliper seal only.
3. Dow corning High vacuum grease.
4. Brake fluid

Each has it own specific application and needs for the task to be performed.

#1 is used to get everything clean.  (given the confusion, it had to be said)
#2 is used ONLY on the seal and must be compatible with #4, as some of it will invade the brake fluid chamber.
#3 is NOT used on the seal, as that would put silicone inside the brake fluid chamber.  This is a bad thing as the compounds are incompatible.  It is used behind the brake pads and a thin coat is used on the parts of the calipers and piston that are exposed to the elements and subject to water ingression.  The Dow Grease will not mix with ANYTHING.  It is a simple barrier with the very important property that it will NOT melt when the parts get hot and then run/creep into the brake pad friction material and provide lubrication between pad and disk rotor.
#4 is what makes the hydraulic part of the brake function. (I hope that part is clear.)

Cheers,

[Ewan 500K1]

For the caliper cylinder seals , red rubber grease can be used.  Tech data sheet here:

http://www.bp.com/assets/bp_internet/castrol/castrol_south_africa/STAGING/local_assets/downloads/t/Red_Rubber_Grease_TDS.pdf
 

[70CB750]

I use NAPA high temp brake grease, fully synthetic. I used it on jeep calipers before with best results.

[TwoTired]

For the caliper cylinder seals , red rubber grease can be used.  Tech data sheet here:

http://www.bp.com/assets/bp_internet/castrol/castrol_south_africa/STAGING/local_assets/downloads/t/Red_Rubber_Grease_TDS.pdf

You could use this in place of the assembly lube.  But, it does not have  high enough temperature stability to be used in place of the Dow corning silicone grease.

[TwoTired]

I use NAPA high temp brake grease, fully synthetic. I used it on jeep calipers before with best results.

The SOHC4 calipers have special needs that Jeep don't have.

"Synthetic" does not mean it won't weep creep or flow with high temps. The Grease category is usually more concerned with lubrication ability rather than placement stability.  With don't need a lube where the silicone grease is placed.  We need a water and oxygen barrier that stays where placed in hi temp environments.

I couldn't find an MSDS for your NAPA description specifically.  Do check that, as it is little comfort to have the grease still function as a lube when it wanders out to the brake pad/rotor interface.

Cheers,

[RAFster122s]

The SOHC caliper design is different than most automotive caliper designs I've ever worked on or seen...
Auto:
I've worked on Lockheed and Girling designed calipers from the late 50s-60s as well as 80s-90s and GM designs from 80s and Ford designs from 90s-2005