Topic: took front break caliper apart

[cadaver]

OK now that I was able to get the caliper apart and cleaned out the rust and other crud .. I cant get the piston back in ..the rubber seal wont let the piston threw...anyone have a trick that you know of . or do i just half to go and buy another seal because that one is warped out ?

[ieism]

Take the caliper completely off. Make sure you've cleaned out the groove that holds the seal> put a little coppergrease on the seal and put it in the caliper. Put a little coppergrease on the inside of the seal.
push in the piston STRAIGHT. It takes a little force, that's normal.

[cadaver]

OK ..ill go out and try that ..but I've gotta run and get some copper grease.  I was just wandering, why copper grease and what is the difference in that and other greases ?

[ieism]

Copper grease is heatresitant. I'm not sure what happens when normal synthetic grease gets in contact with brakefluid. It might corrode or something.
These are your brakes, so don't take any chances.

Just go to a car mechanic/shop and ask him for a little coppergrease. You need less that half a tablespoon, so he'll likely give it to you for free.

[rhos1355]

Better still, buy a spraycan of the stuff and keep it handy for any future greasing jobs

[lordmoonpie]

Copper grease is heatresitant. I'm not sure what happens when normal synthetic grease gets in contact with brakefluid. It might corrode or something.

I think it's more a case with normal grease the heat makes it fluid and it gets everywhere - including on your brake pads. Copper grease stays put and works without putting your neck on the line! 

[Raul CB750K1]

To put the piston back in, once the caliper and piston has been thoroughfully cleaned, I simply use brake fluid as lubricant.

[TwoTired]

Why wouldn't copper grease contaminate the brake fluid?

I use brake parts assembly fluid.  Made specifically just for the task.

Cheers,

[cadaver]

well i went to one of the auto car parts stores around where i live and i didn't see copper grease..and the guy kinda looked at me funny when i asked about it ..but than again maybe he just works their and takes the money ...but i used a lithium grease all purpose ..just a dab and use a C clamp and it worked its way in ...put it all back together and i hope that later on that i can stop  ....but so far when i pull in the break it Locke's up ..and when its off it rolls ..thanks for the help

[Artfrombama]

I used a dab of silicone brake grease and slid right back in with two thumbpower.

Copper grease is a new one on me, must be a European product.

[oldbiker]

If you google 'Granville oil', and look in products/grease you will find copper grease. The makers claim it is good to prevent corrosion especially in hot areas. They also say it stops brake squeal when applied on the back of brake pads.

[bradweingartner]

I always use brake fluid as lubricant too.

If you hook up the brake systems and THEN fill and insert the caliper piston, you eliminate most of the air out of the system in one step. Bleeding is seldom necessary!

[fmctm1sw]

Try buying a new seal.  Made all the difference in the world for me:  http://forums.sohc4.net/index.php?topic=27842.0

I bought a new seal and it went right in with a little brake fluid n it...

[cadaver]

thanks guys for all your input ...but when most of my bike parts come in ill order a new seal and break pad for front and back ..bike has taken way to long to get on the road 

[TwoTired]

Won't lithium grease make the caliper seal swell up?

[bradweingartner]

Won't lithium grease make the caliper seal swell up?

I've never been foolish enough to try, but I know I won't be putting anything besides brake-specific fluids and goops anywhere near my brake system when it's pretty much the one useful brake I got.

[cadaver]

i didn't know if it would but i pulled the seal out and cleaned all the stuff that was in that ring with a dermal ..and i put the seal back in and pushed the piston back in . put it all back together and works for the time being ..when i get my new parts for the front break i don't think that ill use that grease if it makes the seal swell up ..thanks for the advice