GSXR brake upgrade

[Rocket]

I got a '92 GSXR11, kitted the M/C and calipers and fitted HEL braided lines but they're still spongy, and I bled them plenty[V]
I suspect the master cylinder is the culprit as it was in less than perfect condition but I thought it would be okay.

So what do i need to do to fit a later (preferably six pot) master cyl to my bike ?
Would it be too much for the four spot calipers and make them behave badly[B)] ?
Does anyone have anything they want to sell ?

I'd like to upgrade to six spots and bigger discs too if they're an easy fit, but that'll be later on unless the price is right.
Right now, the bike is getting close to hitting the road so i'd better just worry about getting some decent lever for now.

[loosebruce]

Sound like air still in your lines.
If you've got an adjustable lever there are about 4 points it can wear,
try a new one,dissassemble and grease all pivot points before it goes in.
Should make a fair bit of difference if all else is well.

:)

[Booster]

Have you bled at the master cyl banjo fitting?

[Rocket]

Nah but I tried just about everything else. I haqd the M/C off and twisted it in all directions and tapped it with a screw driver etc. di the same to the calipers. Then gave up and told the bike shop to have a go. Came back the same.
I might try the new lever idea as my lever is a bit munted anyway. Then will throw my hands in the air and fit a drum brake.

[Tathagata]

Ive been chatting to Rick Miller about the brakes on my gsxr750 (96). They feel real spongy to me as well, Rick reckons this is normal for the gixxers, especially earlier ones. he said kit it (which you have done) and put in new fluid, those things will help, but he says they will always be spongy. Only way to fix it is to put in brakes from a new gixxer with the floating master cylinder.

Im new to this, so may be stating the obvious to you, dunno...hope it helps anyway.

Stu

[Booster]

My 96 is rock solid with braided lines , same as my busa which uses the same brake system.
Took a bit of fiddling to get it right though as there was an airpocket in the banjo that only went after pulling the lever then cracking the banjo bolt , took 2 or 3 goes to get it all.

[Rocket]

I took Loosey's advice and just ordered a new lever because mine looked crappy anyway.
Booster, I will also try cracking the banjo bolt and see what happens.
I can't live with spongy brakes, at worst, I'll get hold of a late model M/C and run that.
Oh yeah, i have two brake lines running from the calipers to a double banjo bolt at the M/C so there's twice as much chance for trouble.
Will let youse know the result.

Still wouldn't mind some six spots later on, then at least I can fool myself into thinking that i COULD do stoppies if I wanted, I just choose not to.

[Captaintoc]

Yay I'm back on the net again.

Your best bet with the brakes is to get a.(Cheap arse way) a big horse needle from a vet and some clear tube, tefflon tape the the bleeders on the calipers so they don't have any air leaks and push the fluid from the caliper to the M/Cylinder with the syringe - This is how I've done it previously with great results.

B. (Not cheap arse way) get a vacuum tester and bleed them with that as described by the instructions, and if that fails (5% of the time it does) go to the wreckers and get a second hand M/C cover and drill a hole to fit a small hose fitting and seal it and attach pump to it and bleed backwards again.

Have Fun
Andrew

[Rocket]

Thanks Cap'n, I tried changing the lever but as expected, that didn't help as there was no slop in my old lever, but I needed to change it anyway.
I cracked the Banjo bolt and that made a bit of difference but they're still not great though I seem to be on the right track.
Because this is a turbo bike, I'm probably going to need brakes at some stage so i'll try draining the fluid back down the hose a bit with a horse syringe and push it back up and see where that goes.
All I need to do is find a crack hor-se (hahaha)

If that fails, i'll be in the market for a 6 piston M/C.