Topic: Grease from brake cylinder repair kit-What's that for??

[Picasoo]

I was bought a repair set for front brake cylinder... with all common stuff, in package was a little box with some grease in it... what's that grease for???

[graeme7]

I used it to lube the seals before i fitted them.

I guessed that was its intended purpose.

I used the tiniest amount though, seemed like quite a large portion.

No idea if that was its intended use, but it doesnt seem to have done any harm.

[Rigid]

That is to lessen the pain from the shipping charges from Switzerland. 

[tjofle]

It's bad form to refit the seals dry, and since brake fluid is not exactly kind to your skin (or health in general) many people prefer to use grease instead. Personally I just wore a double pair of gloves and lubricated all parts with brake fluid prior to assembly (in a well ventilated area, also known as "outdoors" ).

[raymond10078]

see pic.

[Picasoo]

You make a question and you got some joke, some textual and some pictured answers... all that you need!
That's why this forum is the best!!!

You guys are awesome-thanks a lot!

[Duke McDukiedook]

No, grease and the seal is bad- do not use it.

You should use brake assembly fluid to lubricate the seal before inserting the piston. Brake fluid should be used if you absolutely cannot find brake assemble fluid, brake fluid attracts water so it is not good to use where parts come into contact with air- like seals.

Like kandrtech showed if it is high temperature silicone grease it is meant for the back of the pad to cut down on squeal.

 

[TwoTired]

What, there are no label laws/controls where you live?

I suppose it could be some sort of assembly grease.  IF it is compatible with glycol brake fluid, then it is ok to use on seals and rubber parts during assembly.
But, then it wouldn't be useful for the back of the brake pads and piston, as it would most likely flow, weep, or creep out to the pads and lube them up later when temps get high.

If it IS for the back of the pads, it almost has to be silicone which you NEVER want to mix with glycol based brake fluid (not an assembly grease).
A pure silicone grease should not weep, creep, or melt at temps up to about 500F, and it is NOT simply for the purpose of anti squeal.

The silicone grease is placed there as a water barrier, as the the stock caliper system has no seal to keep water from behind the pads.  A thin coat silicone grease on all metals behind the friction pad will shed water and keep it from corroding the steel and aluminum bits behind the pads.  It is most important that the grease be a pure silicone, with NO petroleum compounds added to it.  Silicone actually combines/mixes with nothing, petroleum compounds can be suspended within it though as bulk filler or for other lubrication purposes, that ARE NOT needed for the SOHC4 caliper design.  But, petroleum will separate out of suspension with silicone with time, heat, etc. and then soak the pads with a lubricating fluid.
It's not usually a good idea to lubricate the friction pads or the rotor.

I believe if I could not easily identify an unlabeled jar of grease, I wouldn't use it, unless I tested its thermal and creep properties with  a range of temperaures, or got accurate information about what it was from whoever you made the purchase.

Modern auto parts stores, and many motorcycle shops have no clue how the 1970's brake caliper design varies from modern equipment, and what it's specific needs really are.  So, don't just take the salesman's word for it.  They aren't really assuming any risk selling whatever they conveniently have.  It's your risk.

Cheers,

[graeme7]

It didnt feel like silicone grease to me.

I havent used silicone grease alot though, only on shower doors. Im a ceramic tiler by trade and have fitted a few, you use silicone grease on the cogs in the folding mechanism.

This pink grease didnt feel like silicone.


As i say, i put it on my seals (why would they give you grease for the pads in a master cylinder seal kit?).

It all seems fine at the moment, but it may have been a bad idea.

Im converting to dual discs soon and will be fitting a new master cylinder. When i do ill take this one apart again and see if the grease has mixed and dispersed.

Might be hard to tell as i only used the tiniest of smears.

[dave500]

it should be rubber grease,,if the assembly is going on the shelf for a while,,as in a change over unit at a commercial shop thats whats used,,if its being pressed into service straight away use brake fluid.

[raymond10078]

TwoTired is right.  There are greases/lubricants designed for rubber brake parts, and others are not compatible with rubber.

Some service manuals direct use of greases/lubricants on master cylinder seals, but this isn't very often.

Clearly, the Honda manual calls for grease on the caliper piston/seals.  The Honda manual only calls for brake fluid on master cylinder parts.

However, if the supplied "stuff" is designed for use on a master cylinder seal, then it is OK for use.  TwoTired stated, and I agree, that unlabeled "stuff" would cause me to pause and call the vendor to make sure what it is, and is supposed to be used for - since they sold you the parts.  Or, I'd just buy the right stuff if you wanted to use similar stuff.

Personally, I use brake fluid for my master cylinder seals, and silicone on my caliper seals.

[wedoo2]

I use a moly grease on the pivot bolts.  Same stuff?

[TwoTired]

I use a moly grease on the pivot bolts.  Same stuff?

Absolutely not.

[Picasoo]

Thanks you guys for all opinions...
I think I will do like Kandrtehc says... I'm finished cleaning, painting with caliper and I was put some grease like on the pic above!!
Master cyl I will lubricate with brake fluid!!
Here is the pic of the grease:

[Picasoo]

Finished...


thanks you all...!!