Crap brakes on a GSXR.

MrStompy · Post by **MrStompy** » Tue Apr 10, 2007 4:45 pm

i do a few bits and pieces to my briother's track bike (03 gsxr 600)
the front brakes were shit on it so we have just put braided lines on it, race compound brake pads and motul brake fluid.

I have bled them about 4 or 5 times to try solve this problem and to ensure there is no air left in there and there definately isnt and there is definately no fluid leaks. I still get a fairly lousy feel out of it. they still feel spongy and there is bugger all room till the lever hits the throttle. Two finger braking is out of the question as there is not enough room between the fingers and the lever when the brakes are applied - so the bike is dangerous really.

What do i do now? there is only 2 components left to replace (the calipers and master cyclinder).

i recently put new lines on my zx6 and the braking is awesome so im at a loss why the GSXR is being so troublesome (except that its a piece of shit).

any tips would be greatly appreciated.

MickLC · Post by **MickLC** » Tue Apr 10, 2007 5:00 pm

There might still be some air trapped near the master cylinder that you won't get out with normal bleeding at the caliper. You might have to crack the banjo a bit at the master cylinder and bleed it out from there...I'm sketchy on the details cos I haven't done it myself.

Gosling1 · Post by **Gosling1** » Tue Apr 10, 2007 5:11 pm

You might have to force the caliper pistons right back into each caliper, to remove any air which is trapped inside the caliper itself.....bleeding with the bleed nipple does not always remove all the trapped air....

Did you bleed from the banjo bolt at the master cyclinder ? This is #1 spot for bleeding, the nipple-bleeding method takes ages and doesn't always give a good result....

The easiest way to do this ( I just saw Mick C's post), is to place a large towel under the master cylinder, draped over the tank/frame/fairing etc, all the stuff that can be damaged by brake fluid.

Pump up the brake, someone else to help is always good, hold the brake lever in, and 'crack' open the banjo bolt. If there is any air in the system, it will find its way up to the banjo bolt, because air trapped in any hydraulic system will always tend to rise, not fall......

Once you have 'cracked' the banjo open - at all times keeping the brake lever compressed - and some air has escaped ( and fluid, all over the towel you have strategically placed

), then re-tighten the banjo bolt and repeat.

This is by far the best way to bleed brakes, directly from the m/cylinder. If you want, rotate the m/cylinder as well, so the banjo junction is the highest point in the brake system.....this will help with any air trapped inside the m/cylinder as well - Obviously the m/cyl cap will be on tight if you rotate the m/cyl a bit.....

If this method fails, then you need to bleed the calipers individually, and also the brake junction (if it is still fitted).....

If all this fails, the seals in either the m/cyl or calipers are rooted, and you will need to either put a kit through them, or replace with Kawasaki brakes, which work a whole lot better anyway !!!

MrStompy · Post by **MrStompy** » Tue Apr 10, 2007 8:19 pm

thanks for that Mick and Gos
im going down to try it now.

Gosling1 wrote: replace with Kawasaki brakes, which work a whole lot better anyway !!!

sounds like a good idea idea to me

will let you know how it goes

MrStompy · Post by **MrStompy** » Tue Apr 10, 2007 8:34 pm

didnt work

is putting a kit through it a DIY job or is it a bit tricky?

thanks for the help.

ttc · Post by **ttc** » Tue Apr 10, 2007 8:36 pm

EBC pads are very good

Gosling1 · Post by **Gosling1** » Tue Apr 10, 2007 8:41 pm

MrStompy wrote:didnt work

is putting a kit through it a DIY job or is it a bit tricky?

thanks for the help.

I'd recommend getting a kit done by a specialist - you need to hone the bore of the m/cyl, install new seals etc, its a bit tricky for DIY....maybe you could do the calipers yourself, but you need the right tools as well.

EBC HH pads are the go, as per ttc advice.

MrStompy · Post by **MrStompy** » Tue Apr 10, 2007 8:52 pm

cool thanks for that - i didnt want to start pulling it apart just to discover i dont have the correct tools to do it (or the skill). I will get it looked at by a pro

im pretty sure the pads i put in it last night for him were EBC - but i have no idea how much better they are cause i cant get good enough brake pressure.

Neka79 · Post by **Neka79** » Tue Apr 10, 2007 9:06 pm

hmmm id suggest pulling apart and cleaning the calipers too..amazing how much brake dust and crap can get in there.... that and a m/cyl rebuild kit should fix it...

i have never heard that gix had shit brakes..

MrStompy · Post by **MrStompy** » Wed Apr 11, 2007 8:16 am

Neka79 wrote: i have never heard that gix had shit brakes..

This gixxer has shit everything

its slid up the road about 4 times now so i have to give it credit it is indestructable.

I-K · Post by **I-K** » Wed Apr 11, 2007 10:11 am

MrStompy wrote:cool thanks for that - i didnt want to start pulling it apart just to discover i dont have the correct tools to do it (or the skill). I will get it looked at by a pro

No need for that just yet...

...every time I go to install braided lines, I get confronted by a more boggling reason for why my brakes won't pump up.

The first time I did anything seriously brake-related, it was a master-cylinder swap on my FZR600. Pump, pump, pump, bleed, bleed, bleed, nothing, no meaningful pressure on the lever. Crack the master cylinder banjo, pump, pump, pump, stiff lever. Hurrah.

Next time, braided lines on the R1. Same story. On that occasion, it too cracking the banjo bolts *at*the*calipers*, as well.

Time after that, on my last ZX9, it took cracking all three banjos, followed by leaving the lever tied back to the bar overnight.

Most recently, on my current ZX9, it took, wait for it... pulling the brake lines off completely, putting on just one line, getting that firm, then pulling off the master cylinder banjo again to insert the other line back in.

It's pretty unlikely that a four-year-old bike will have a fuX0Red master cylinder; incidentally, the Eaglebeak GSX-R uses the same master cylinder as the Kawasakis with the six-piston Tokico calipers. I'd try everything in my rainbow of dodgy front brake fixes I've outlined above before going that far.

Neka79 · Post by **Neka79** » Wed Apr 11, 2007 10:29 am

we did my z the other night...no probs at all, but we started by bleeding the master cylinder...

heres a tip..u can buy a bleedable banjo bolt (has nipple---ohhh i love nipples) ..made bleeding the m/cyl piss easy...

JetPilot · Post by **JetPilot** » Wed Apr 11, 2007 8:36 pm

Ive never had a problem with my 03 gixer 1000. Brakes are great. Motor is fantastic. Great handling... But nothin beats a Kawaka...

I would go with the rebuild... sounds like a real pain in the ass.

MrStompy · Post by **MrStompy** » Wed Apr 11, 2007 10:29 pm

im going to give it another shot tmw night but i dont hold my breath. the brakes werent fantastic to begin with so im not surprised that they are getting worse.

goanna_38 · Post by **goanna_38** » Wed Apr 18, 2007 7:47 pm

Brakes are tricky bastards. Look at the whole system and remember that air will always accumulate in the highest point. Study the system, look for high points you have overlooked, imagine where the air will be hiding, be the air (sorry, got carried away). Just kitted the calipers in my ZZR1100. To get all the air out of the calipers I had to pull them off halfway through and rotate them so the pistons were stacked vertically. The passage to get fluid/air from the bottom pistons to the top is about 40 degrees from the vertical and it was trapping air in the bottom pistons. Had a similar problem in my old GPZ900, had to rotate calipers to get them air free. Don't forget the snout of the master cylinder, they generally point uphill and there might be a bit of air in there as well. Rotate the bars to the left and lay the bike over on the left hand side as far as you can to make the piston end the high point. Stroke the lever a few times and any air in the cylinder should come out of the bleed hole and back into the reservoir. Never hurts to rap the master cylinder or anything else you are bleeding with the plastic end of a big screwdriver to shock any air bubbles that might be clinging on and helping to get them moving.