Motorcycle stuck brake piston.

[Ilovecbrs599999]

So a stuck piston is my problem.

I have decided to reconnect the master cylinder to the caliper via the brake hose and use the way the actual brakes work to get the piston out. I am just curious about the following below:

If I could use water for now as the fluid to get the system out- no gloves, no special area, no toxic liquid substance especially right now in the dark and cold outside- it would be so so much easier.
I could get started and get over the excuses, but can I do it with water then drain the system then fill with brake fluid tomorrow morning when setting up on the bike tomorrow morning. Or will that wreak havoc on the system if there's a little bit of water in it and it mixes with the brake fluid tomorrow? (unless there's a way to completely dry it out even the inside of the hose which I can't get into because of the eyelets on both ends and not actual access.)

Thanks.

[freddytin]

Have you thought of using an air-line / pump ?

[Happy Jim]

Removing the current brake fluid will give you as much hassle though.

Connect the calliper to the hose, drop it in a plastic bag, squeeze the lever to pop the piston out. Stuff a couple of sheets of kitchen paper in the plastic bag to mop up the spilt brake fluid.

Don’t over think it.

Jim

[Ilovecbrs599999]

fancy equipment is not available to me- all I have is the brake system as it is.

the system is already completely drained. it is dry- no liquid of any kind in any of the caliper, hose or master cylinder.

so is my proposition safe?

[finlo]

The master cylinder may start rusting on the inside before you replenish the fluid causing you even more problems.

[Boosted LS1]

Open the bleed nipple and refill with brake fluid. Then pump the piston out. Why is it stuck, lack of use?

[Ilovecbrs599999]

correct. i rode without a rear brake for 3 months. irresponsible I know

[GreenV8S]

Boosted LS1 said:

Open the bleed nipple and refill with brake fluid. Then pump the piston out.

^^ That.

I wouldn't ever put water in there. It would be very difficult to dry properly afterwards and inevitably you'll end up with water contamination in the brake fluid afterwards.

If you're using the brakes to pump the piston out, a technique that can come in handy is to put a wooden board where the brake disc would normally go to catch the piston.

Is it very expensive to replace the whole caliper? They are often not expensive compared to the time and parts needed to rebuild an old one, especially if it has a serious problem such as a seized piston.

[finlo]

Boosted LS1 said:

Open the bleed nipple and refill with brake fluid. Then pump the piston out. Why is it stuck, lack of use?

He'll never pump the piston out with the bleed nipple open;)

[Boosted LS1]

But it'll be fun waiting while he works it out.