Sad brakes... 86 GSXR750

[sedge]

I've got sad brakes...

They've had a deca piston kit in them (the callipers I guess), they have braided lines, the pads and rotors look OK, I've flushed out the fluid and replaced it... Still, when I'm braking the lever pulls back nearly to the bar.

The lever doesn't seem to engage the master cylinder and have an effect quickly enough, the brakes work well enough though, I just like to have a little more lever room left for emergencies.

What would cause this ?, I'm thinking maybe I need to shim out the lever acting on the master cylinder, can this be done ?

Cheers,

Sedge.

[dhunt]

Sort of sounds like my brakes. Work pretty good but just have to pull them in pretty hard before they do anything. I was thinking of putting in new brake fluid but it seems you have tried all that.

[FROSTY:Me]

I remember that being a common fault on all of the early gsxr750/1100's
I think it was summat to do with the floating disks moving too muchwhen they wear out.

[riffer]

Huh. Brakes, don't talk to me about brakes.

I finally got mine totally sorted, they work absolutely brilliantly, stand the bike on its nose, but it's lasted about two months I guess.

Now I have a shudder when I pull the brakes on. Damn. :disapint:

[cycosis]

Curious.Did someone help you with the bleeding of the brakes?

[sedge]

I sent the bike in for a proper service... I've re-bled since then just in case that was the problem, but there wasn't any air in there... ??? I'm thinking I might pull the master cylinder and have a look at it. The other option is that the rotors\pads are too thin (ta XJ\Frosty). The brakes are OK for the road, just not confidence inspiring when you can squeeze to the bar, I guess I could try bending the lever out more

Sedge.

[F5 Dave]

Huh. Brakes, don't talk to me about brakes.

I finally got mine totally sorted, they work absolutely brilliantly, stand the bike on its nose, but it's lasted about two months I guess.

Now I have a shudder when I pull the brakes on. Damn. :disapint:

Welcome to the yamaha warping disc club. We meet at 7 on tuesdays (mines just restarted this weekend, poos.

Ducati brembo discs should fit.

[Blakamin]

Welcome to the yamaha warping disc club. We meet at 7 on tuesdays (mines just restarted this weekend, poos.

Ducati brembo discs should fit.

I'm glad i got my honda because that is exactly what the zeal did :disapint:

[kerryg]

I've got sad brakes...

They've had a deca piston kit in them (the callipers I guess), they have braided lines, the pads and rotors look OK, I've flushed out the fluid and replaced it... Still, when I'm braking the lever pulls back nearly to the bar.

The lever doesn't seem to engage the master cylinder and have an effect quickly enough, the brakes work well enough though, I just like to have a little more lever room left for emergencies.

What would cause this ?, I'm thinking maybe I need to shim out the lever acting on the master cylinder, can this be done ?

Cheers,

Sedge.

Sedge

A possible solution (well, partial solution at least) is to fit a straight brake lever instead of the dog-leg lever that's on it now. That will give you more lever travel/leverage. I would be VERY cautious about putting a spacer in between the lever and the piston in the master cylinder. The risk is that you will compromise the master-cylinder's ability to vent and find yourself grinding to a halt as your brakes seize.....most likely to occur when your fluid is hot (i.e.when you are going very fast...). This has happened to some people....

The rotors are worth a look too.

[SLIDER_STEVE]

It might be that your rotor is worn thin, which can be compensated for by fitting a thicker version of the original disc pad - i.e. FA85/2 in parts talk - but check with your parts dealer as to the thickness of the new pad - it might be thinner then the original!!

[soundbeltfarm]

got an 86 gsxr here and my brakes are the same.
i changed oil ..same problem
had them looked at and they couldnt find any probs.
just learnt to live with it.

[scumdog]

Sedge

A possible solution (well, partial solution at least) is to fit a straight brake lever instead of the dog-leg lever that's on it now. That will give you more lever travel/leverage. I would be VERY cautious about putting a spacer in between the lever and the piston in the master cylinder. The risk is that you will compromise the master-cylinder's ability to vent and find yourself grinding to a halt as your brakes seize.....most likely to occur when your fluid is hot (i.e.when you are going very fast...). This has happened to some people....

The rotors are worth a look too.

Just another point of view, I fitted a 4mm spacer at the front of the pushrod on my old H-D, made a hell of a difference and no seizing problems, I did it kind of scientific like and pre-measured to see that there still would be a 2mm (or thereabouts) play when the spacer was fitted to allow for expansion etc.
Sometimes the pivot pin on the lever can wear which means you're pulling the lever back for a bit before it takes up the 'slack' and starts working - check for that.
I've riden a few bikes where you could get the lever to touch the handle-bar be squeezing it hard with one hand - not good! Imagine a fold in your glove getting between the leverl and the 'bar when you're trying to do the 'panic stop from hell'!!