Spongy front brake

[fraserdog]

The front brake on my 02 has always been a bit "spongy",I've changed the fluid,bled it,tried the tie the lever to the handlebar trick but it's never felt right.I read somewhere that you can swop the master cylinder with one with a bigger bore from a different make of bike but I can't remember what from and I can't find where I read it,any info greatly appreciated.

[KuzzinKenny]

Hey fraserdog !! before ya do anythin drastic try this.......

its a bit of a faff but worked for me, you need to remove 1 calliper from the carrier, the one at the end of the fluid line (not from the pipe)
find a block of wood that fits in between the pads and tie it in, you need to tie the calliper up higher than the mudguard as thats where the problem is, air always rises to the highest point so sits there.

now bleed the brakes again, start with the first in the line and you should be able to chase all the air out now, refit the calliper, pump up the lever (WITH the cover on) don't ask  top up the fluid and test !! hopefully you will have a firm brake 

good luck

KK 

[Bixxer Bob]

I followed Kenny's advice and - because I had plenty of time -  taped a small power tool to it thinking the vibration would help dislodge any air bubbles.  Either way, it worked, I had the best front lever I've ever had on the Tiger.  It only lasted a few hundred miles though and now I'm back to the spongy front end. 

Maybe a different master cylinder is the answer....

[fraserdog]

I haven't tried Kennys method as yet but when I tie the lever back to the bars and leave it overnight I have a cracking front brake for a few days then it goes back to spongy again.My 1100 Kawasaki has basically the same size discs/calipers hose lengths and the brake is spot on,the master cylinder looks exactly the same with the exception of the sight glass being in a different place,i might source one the same and try it on the Tiger and see what that does.

[Chris Canning]

From my experience I'd always point the finger at the calipers based on having changed from stock calipers on my 1100s to AP's and then changed them again to PFM's while still having a stock master cylinder there was a major difference between all 3

(http://s64.photobucket.com/user/wing2541/media/Arinsal033-1.jpg.html)
(http://s64.photobucket.com/user/wing2541/media/2014-02-24140854_zps8caa2586.jpg.html)

When I had stock calipers on the tiger had similar poor feel and that was resolved with Beringers the lever is now like concrete so it certainly isn't the mast cylinder

(http://s64.photobucket.com/user/wing2541/media/bikewheel-1.jpg.html)

I have an Xt660 SM that I wasn't happy with brake wise changed the front disc from stock to EBC and changed the master brake cylinder to a radial it's better but I expected much more.

(http://s64.photobucket.com/user/wing2541/media/001_zpsfe65146e.jpg.html)
(http://s64.photobucket.com/user/wing2541/media/015_zps9222c833.jpg.html)