Brake fluid reservoir - educate me please

[tomasj27]

Hey guys, new here just bought a 57 FZ6 for my first bike and have today changed my brake fluid. I have searched (evidently unsuccessfully) to find out what the rubber hollow mould thing inside the rear fluid reservoir is? It attached to the cap and is like a flexible cup that sits in the fluid. I don't need to fix it or anything I'm just curious to know what it does?

Thanks in advance, Tom.

 

[dart1963]

just a way to minimize air inside the reservoir and it's your seal between the cap and tank.

 

[tomasj27]

Thanks, thought it would be simple but it's nice to know. Curiosity killed the cat and all.

 

[Chucker]

Make sure you press it back up into the lid, while keeping it clean. The idea is that it is flat when the reservoir is full, but as the fluid goes down, it fills the void.

 

[tomasj27]

Make sure you press it back up into the lid, while keeping it clean. The idea is that it is flat when the reservoir is full, but as the fluid goes down, it fills the void.

I' very glad you said that.... off to the bike I go!! haha Thanks.