Brake calliper silicone grease

[b_1_rd]

Hello all.  First proper post here.  It’s a great forum, not needed to ask anything until now as I’ve found everything on here. 

Anyway, I bought some silicone grease from eBay (linked below) to use when rebuilding the front brake, being that the service manual specifically says to use silicone grease.  However, I was expecting it to look more like Vaseline rather than a pure white substance.  Do you think this is OK to use?

https://www.ebay.co.uk/itm/176142977635?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=hLpBCXjVTLe&sssrc=4429486&ssuid=HrRpbikaRsi&var=&widget_ver=artemis&media=COPY

[Johnny4428]

Hello, that looks like you just want to add a bit of fruit on top! Yummy!🤣 (sorry)
For what it’s worth I had a tub of silicone grease here for a while that just looked exactly the same. All used now so sure it was ok.

[b_1_rd]

Yes does look good enough to eat 

[deltarider]

Ate grease is - or used to be - first choice and was used by professional mecs. The tube says: compatible with: brake fluids DOT 3, DOT 4 and DOT 5.1. It's expensive though, so I wonder what alternatives there are. Some suggest you may use vaseline just as well. I don't know about the latter.
But that Ate grease is made for the brake job and therefore 100% safe.

[K2-K6]

I've only used a clear silicone grease for many years.

Unsure what's in that SK22 (doesn't mean it's poor, just really hard to find conclusive information) but note it's food grade product and likely suitable for that type of production line equipment etc.

From safety sheets, it more or less won't do you any harm if you did eat it  effectively non toxic and pretty inert in reaction to anything.

White coloured grease often have zinc oxide in them and pretty inert in that form generally (think that's in "Sudocreme" for babies etc) but could be talcum powder as that product refers to anti spatter properties,, logical if used on rotating shafts or similar in food production.  Looks like it could do the job, but I've no experience of using it.

For reference, I'm currently using this https://www.ebay.co.uk/itm/134181635084 for any silicone grease application. Plumbers supply also do convenient small tubs of clear silicone grease to, usually easily available locally.

[Bryanj]

It does say silicone grease but not on the seals, only the pad rear and suround

[McCabe-Thiele (Ted)]

My silicone grease is clear it's food grade - not to keen on the white version in the earlier posts.

[K2-K6]

We can look at product suitability.  There's reasonable cause to consider what we know currently in comparison to that which people have been used to over the years. It's clear to me that silicone grease is suitable to fit brake component together in place of what may have been used previously. Honda manual originally published in late 1960s is clear that silicone is to be used around the outside of the piston and seal "area" and pad to caliper bore too, not making a statement of use ON the singular seal. Stating the temperature range of that silicone grease as   -55~200 C and "do not use Molybdenum grease" its very specific and matches the product specification of currently available product, in so far as the details that are available.
Contemporary view is that silicone grease IS suitable for assembley of the hydraulic seal, making it a one shot solo product with suitability for this task. This, water exclusion, being the most effective way to mitigate galvanic corrosion that produces the degradation around the piston from any road salt ingress that gives electrolyte capability, then eroding the aluminium to produce that characteristic and typically white corrosion, which ultimately seizes the brake piston.
It is highly water repellent, one of its most useful attribute, as it (from my, anecdotal experience) has verified to ME. Whether that's of interest you'll have to consider for yourselves.

Some specific product reference here, proprietary brand but the basic ingredient (without marketing puff) is the same silicone grease in these available brands.

"Super Lube® Silicone Lubricating Brake Grease with Syncolon® is a NLGI Grade 2 compound designed for caliper and wheel cylinder assembly work as silicone is an excellent lubricant for rubber and plastics. It is compatible with the majority of rubber compounds including nitrile, nylon and other synthetic rubber. See Compatibility Chart under Technical Resources for further details.

Super Lube® Silicone Lubricating Brake Grease should be used at every point in the brake system where parts slide or move. With disc brakes, lubrication points include: caliper slides, pins, bushings and contact points where the pads slide within the caliper housing. It can be applied on self-adjuster mechanisms on rear disc brakes with locking calipers, parking brake cables and linkages.

Super Lube® Silicone Lubricating Brake Grease can also be used to dampen vibrations between disc brake pads and caliper pistons. It should NOT be applied between the pads and any noise suppression shims. Use it sparingly on the back of a bare pad or between the pad shim and caliper.

Super Lube® Silicone Lubricating Brake Grease is dielectric, food grade, clean and environmentally friendly. This product is an NSF registered Food Grade lubricant, rated H1 for incidental food contact and meets USDA 1998 H1 guidelines.

Super Lube® Silicone Lubricating Brake Grease is Kosher Certified.

For more information on how to apply our brake grease, click here."

https://www.super-lube.com/silicone-lubricating-brake-grease-with-syncolon

Anecdotal experience, I've used variously silicone brake fluid and grease in brake system since the 1980s, taking contemporary advice then from brake product manufacturers, built systems in competition use some running disc temperatures up until they are yellow  designed,   manufactured and maintained components with these materials. Its extensive but I wouldn't consider myself expert, just diligence in appraisal of these materials.
Certainly not a directive in any way on my part, but if there's a counter to this it should be able to hold it's own in reasoning to let others judge for themselves and make valued desicions on their own behalf.
Oh....and backed by metallurgy view from a career metallurgist....also the same from a career employed analytical chemist 

[b_1_rd]

Wow thanks all that’s great information.

Amazing amount of info, thanks K2-K6.

I’ve ordered some other silicone grease (NLGI 2 grade) just to be safe and will just use the existing tin for general purpose stuff.

What’s the recommendation for the seal? Leave it clean and dry or smear brake fluid etc?

Thanks again.

[McCabe-Thiele (Ted)]

Wow thanks all that’s great information.

Amazing amount of info, thanks K2-K6.

I’ve ordered some other silicone grease (NLGI 2 grade) just to be safe and will just use the existing tin for general purpose stuff.

What’s the recommendation for the seal? Leave it clean and dry or smear brake fluid etc?

Thanks again.

Back in the day most car wheel cylinder kits all came with a small sachet of red lubricant - I always assumed it was red rubber grease.

[K2-K6]

For the seals, I put them in using silicone grease (this seems contentious though) after thoroughly cleaning the the seal groove.

On anything I've completed though it has been long lasting and the most successful I've yet found.

I disagree with using brake fluid, it obviously works, and with zero risk as recommendations go, but favoured silicone grease specifically for the protection against corrosion longer term.

Everyone will have to form their own opinion as to what they are comfortable with though.

[K2-K6]

Wow thanks all that’s great information.

Amazing amount of info, thanks K2-K6.

I’ve ordered some other silicone grease (NLGI 2 grade) just to be safe and will just use the existing tin for general purpose stuff.

What’s the recommendation for the seal? Leave it clean and dry or smear brake fluid etc?

Thanks again.

Back in the day most car wheel cylinder kits all came with a small sachet of red lubricant - I always assumed it was red rubber grease.

Yes I remember those Ted and one of my first trusted tasks given to me by my dad. A little sachet to squeeze onto the components within car wheel cylinders when changing pistons/seals. Brakes always seemed to be quite marginal on cars from my early memories    with drums all found on old BMC stuff.

A little square spanner too for adjustment of shoes when the drum was back in place, a little ritual of maintaining them.

Also gapping the spark plugs as the earth electrode wore down, by tap, tap, tapping it on the rocker cover bolt of A series BMC motor. I felt really important given that responsibility and with a set of feeler gauges to work with 

[b_1_rd]

Brill. Thanks everyone. 

[ST1100]

Ate grease is - or used to be - first choice and was used by professional mecs. The tube says: compatible with: brake fluids DOT 3, DOT 4 and DOT 5.1. It's expensive though, so I wonder what alternatives there are. Some suggest you may use vaseline just as well. I don't know about the latter.
But that Ate grease is made for the brake job and therefore 100% safe.

Second that, using it for all MC and SC overhauls, brakes or clutch... 

[K2-K6]

There's some general restrictions on usage of different product.

Petroleum based ( vaseline etc) you'd not use unless specifically demanded by manufacturer direction, unlikely in what I've seen.

The ATE paste for assembley, appears to have the same properties as traditional red rubber grease in its directions, notably it's not compatible with silicone fluids, if anyone was to think about that combination. Red rubber grease is I understand vegetable oil based

Excerpt from ATE published directions in regard to THAT ATE product noted above.

"ATE brake cylinder paste
The brake cylinder paste is used for the repair, assembly
and corrosion preservation of internal brake components.
Its lubricity also enhances ease of fitting, especially of
rubber parts on metal surfaces.
The brake cylinder paste is not splashwaterproof. Its use
is therefore restricted to internal surfaces in protected or
sealed installation positions.
The brake cylinder paste is used for hydraulic brake
systems designed for operation with brake fluid based
on polyglycol ethers according to the standards FMVSS
116 (DOT 3, DOT 4, DOT 5.1), SAE J1703 and DIN ISO
4925. It is not planned for usage in brake systems with
a silicone or mineral oil based hydraulic fluid.
Although, as a rule, plastic components (such as pis￾tons) which are resistant to brake fluid are also resistant
to the brake cylinder paste, the compatibility of plastics
with brake cylinder paste must be tested. The same
applies to organic coatings.
The brake cylinder paste must be kept away from the
surfaces of friction linings or brake discs.
The paste has a long-term temperature stability ranging
from -40° C/ –40° F to 100° C/212° F and temporarily
resists temperatures up to approx. 200° C/392° F.
The brake cylinder paste is available in
3 consistencies:
Consistency Container Item code
pasty 180 g tube 03.9902-05xx.2
soft 5 kg bucket 03.9902-0503.2
40 kg bucket 03.9902-0504.2
free-flowing 5 kg bucket 03.9902-0505.2
40 kg bucket 03.9902-0506.2
The brake cylinder paste is not a lubricating grease with
a stable consistency. Under the influence of mechanical￾dynamic processes, such as flowing and stirring, an
increasing reduction of consistency occurs which disap￾pears again when the process ends. Thus, the specifi￾cation of a defined viscosity value is not reasonable.
Above approx. 70° C/158° F an increasing liquefaction
of the thickener sets in which is almost reversible on
cooling down.
Specific values:
n Dropping point for pasty tube quality (DIN ISO 2176):
<80° C/176° F
n Flash point of base oil (DIN EN ISO 2719):
>145° C/293° F
n Low-temperature stability (all consistencies)
after storage at –30° C/ –22° F for 1 week:
soft, brushable
after storage at –40° C/ –40° F for 24 h: not solid
n Swelling of rubber (DIN ISO 4925 Item 5.11, determined
on SBR test cup seal RM-3a, 70 h/100° C/212° F):
Change in volume: 0 to +6%
Change in hardness: 0 to –10 IRHD
The brake cylinder paste shall be applied as a thin,
uniform film or in dots applied by means of an automatic
lubricating system.
Contact of the brake cylinder paste with friction lining
surfaces and brake discs must be avoided.
n Shelf life (information for a storage temperature from
0° C/32° F to +40° C/104° F):
Tubes: 3 years
Buckets: 2 years
When not in use, the container must be kept tightly
sealed.
During storage and transport of the paste, changes
of consistency (rigidification) or partial separation may
occur, especially when the maximum storage tempera￾ture is exceeded. This behaviour, however, does not
adversely affect the usabilty of the paste. A consistency
which permits the usage of the paste can be reestab￾lished by mechanical treatment of the paste (e.g. agitat￾ing), if necessary by additional warming to a maximum
temperature of +40° C/104° F.
On agitating, it has to be made sure that no particles,
e.g. from the container, from the agitating tool or by
exterior contamination get into the paste which may
adversely affect braking components on application of
the paste.
A Safety Data Sheet as well as additional information
regarding this topic are available under www.ate.de."