Master Cylinder pieces

[conkeyro]

Finished installing the braided brake lines on my FJ1200 rescue and went to bleed them.  Found this inside of the master cylinder.  I removed it before making a mental note of if it was installed smily face up or smily face down.  Tis part does not show up on the parts list.  What is it and what does it do?  does it get installed smily face up or down.

Thanks for any help offered.

Bob C

[Waiex191]

I don't think my '89 had one.  I now have FZ1 brakes. Could be for bleeding with the cap off, to keep the brake fluid from squirting up and out.

[racerrad8]

Bryan nailed it. This is there to prevent the small squirt upwards when the brakes are applied.

It does not matter which way it it installed, just don't push it all the way down. Leave a couple of mm gap.

Randy - RPM

[conkeyro]

Thanks to Bryan and Randy.