Leaky Master Cylinder?

[lth]

Hi all,

The last time I rode (November or so) I found my front brake was squishy--could squeeze it almost to the handgrip--so I did the only thing I know how to do: bled the brakes.

- Bled the right front. No effect
- Bled the left front. No effect
- Bled the valve by the master cylinder. Brake pressure nice & firm again.

I went for a ride, everything was fine, and parked the bike again. Didn't touch it for two months. Then on one of our recent warm days, I found the brake squishy again. This time I didn't do any troubleshooting; just didn't ride.

So,

- Is it a leak somewhere around the master cylinder?
- If so, should I be able to visibly see it?
- Are there tests you recommend to see if it's something else?
- Should I just replace the whole thing--MC, brake lines? Cheaper than replacing things one at a time?
- Any other advice?

The bike is a 2005 GSX-R1000, stock everything. Stored inside a garage. Had it since 2009, no problems before this.

Thanks!

[frank2]

I also have a K-5 1000. Never had your issue, but it sounds like you're sucking air or something isn't tight, like a zirk fitting or maybe a slight crack at MC reservoir that does not show itself right away.