1997 GSXR Brakes

[Davie_GLA]

Afternoon all.

I'm beginning to believe that the brakes on these are as bad as people told me before i bought it.

So, to try and remedy this i bought a set of goodridge braided lines in road config, fitted them and used the worlds reserve of brake fluid bleeding them.

They do feel a little better but i can still easily pull the lever back to the grip and thats with the lever set to the farthest away span setting.

I bled at the master cylinder and both callipers until i couldn't feel my right hand.

Is this just the way it is? Would a master cylinder help? Is there simply just some more air somewhere?

Not a show stopper but there have been times where some more feel through the lever would have been welcome.

I'm planning to do do a track day this year and would like it sorted before then.

D.

[GingerJonny]

Hey Davie, that sounds pretty bad, in my experience lever to bar is never good. With braided hoses on the lever should be pretty solid. One way to tell if the master cylinder has gone is to quickly pull the lever back, if you get initial resistance then it fades as the lever creeps to the bar, then i would be looking at a master cylinder. If it just feels the same soft mush then it must be air in the system. Try bleeding the brake's with the callipers up above the master cylinder(as air always wants to rise) with the pistons pushed back and a lump of wood stopping them popping out . Also make sure you keep tapping the brake hose all the way along to the calliper, as tiny air bubbles can stick to the sides, this loosens them off and lets them out. Another thing you can do is create a loop from your bleed nipple back to the master reservoir with some tube.. then you can go crazy and not go through gallons of fluid. The last extreme trick is to reverse bleed it by forcing fluid in the bleed nipple up and out of the master reservoir... Best to do this off the bike lol.. You can force the fluid by connecting the brake calliper nipple to a car's bleed nipple via tube and very gently press the car footbrake.. Lol all sounds daft but it always works for me when brake/clutch line's wont bleed.. Failing that try voodoo + dance

[Stevie_P]

Sounds like the seals in the Master Cylinder could be leaking fluid back.

[Davie_GLA]

This makes me angry.

I rebuilt the master cylinder about this time last year, so it can only be air or the master cylinder is worn.

I looked at brembo MC's but they are huge money for a road bike. Maybe it's time i got the finger out.

I guess i'm learning what owning a 12 year old reasonably fast bike is like to own. I think i must have put £2k into it over just under three years.

But i love it.

i think i'll go for another round of bleeding and see how that goes.

Edited by Davie_GLA on Monday 27th June 16:00

[C8PPO]

Get a master cylinder from a K6 Thou from eBay - will transform the brakes. (Alternatively lash out for a Brembo m/c, but no need really). I did this on my track 600 and it was the single best mod I put on it.

[Davie_GLA]

i'd heard this about the K6 - will it go on with little fuss?

[C8PPO]

Yes, it does. Only two things I remember are:

- you *may* need to change the brake hose, depends on how the entry union is configured (ie whether it fits or not!)

- check that you're not fouling the fairing with any part of the m/cyl at MOT time - you may need to rotate it slightly.

It makes a world of difference, with no other mods to the braking system. Probably get the m/cyl for less than £50. Here's one: http://cgi.ebay.co.uk/SUZUKI-GSXR-K5-K6-FRONT-BRAK...

[Davie_GLA]

Having just bought some braided lines i'd be annoyed if they didn't fit.

i've just been out again and bled both calipers and the MC again. The lever travels a good 20-30mm before any resistance is felt.

I'll get a k5/6 MC and see how it goes, if it doesn't fit I doubt i'd have trouble selling it on again.

Could the calipers themselves be causing any of this?

[moto_traxport]

Davie_GLA said:

Could the calipers themselves be causing any of this?

With 12 year old Tokico 6 pots I'm suprised everyone's talking about the master cylinder. Rip all the dust seals out of the calipers and be done with it.

[Mellow Matt]

If it's any consolation my 1999 TL1000R has the same problem and my attempts at bleeding the brakes and fitting braided lines have made no difference!

On the other hand, I have a 1999 GSXR 600 and the brakes on that are fine!

I'd be intrigued to see if you manage to fix it

[Davie_GLA]

I'm becoming obsessive now - if a K6 MC and a caliper rebuild doesn't do the job the next 2 things i'll buy will be some lighter fluid and matches.

[Davie_GLA]

Can anyone tell me the advantage of fitting the K6 MC? I read it's radial but i'm not sure why that's better?

EDIT - is it just that the plunger is travelling in the same direction as the lever giving better 'feel'?

Edited by Davie_GLA on Tuesday 28th June 09:06

[C8PPO]

moto_traxport said:

With 12 year old Tokico 6 pots I'm suprised everyone's talking about the master cylinder. Rip all the dust seals out of the calipers and be done with it.

Whilst it may well be that the calipers need a service as well (and maybe the m/cyl is also in need), the K6 m/cyl makes a massive difference anyway even to a "good" set of SRAD brakes.

I can't actually give you the technicals on why but I assume it's to do with the piston ratio and the amount of pressure delivered to the calipers. What I objectively say is that the brakes on my SRAD were quite scary at times before fitting the K6 part, and worlds apart afterwards - ie, a firm lever, minimal travel, easy modulation, etc etc. I would regularly outbrake a 2 mates on a 1098S/2006 Blade on track - that's not a boast, just a fact, and of course it could all be down to skill levels/nad size anyway!

[VB]

I fitted a Brambo Radial MC to my 7R (which I believe has the same 6 pot Tokico set up) from an R1. The only thing to be aware of when fitting is to make sure you have enough room on the clip-on for the switch-gear.

I had to fit an R1 switchgear (could have used anything else really) & then fitted a 1/4turn throttle assembly, which then meant new throttle cables, so the job turned out a little bit bigger than I expected

I've got some pics somewhere that shows how it ended up.



I bought the MC second hand from the owners forum and I have to say the overall stopping power didn't change much, but the feel from the brakes was much better, which in turn led to increased confidence when entering corners on the brakes.

Edited by VB on Tuesday 28th June 10:29

[Dr Doofenshmirtz]

We get this question so often on here...

The ONLY way to properly bleed bike brakes is to reverse fill them.

Method:
Get yourself one of those large syringes...the sort of size that would make you feint if a doctor came at you with it.
Then using a piece of hose, fill the syringe with brake fluid and then slowly fill the system from the bleed nipple on the calliper. When you see fluid coming out of the master cylinder reservoir, stop, and do the other calliper.
keep reverse filling until you see no more bubbles in the reservoir. You will probably need to syphon some fluid out of the master cylinder reservoir during this process.
Once you are happy that no more bubble are coming up through the system, bleed the system in the traditional way just to make 100% sure all the air is gone.

Others will have their own ideas - but this is the only method that works 100%.
HTH.

[Davie_GLA]

Thanks, is this true for systems like mine that have a system whereby both calipers are fed from the one hose? So there is a hose from caliper one over the wheel to caliper 2?

[Dr Doofenshmirtz]

Davie_GLA said:

Thanks, is this true for systems like mine that have a system whereby both calipers are fed from the one hose? So there is a hose from caliper one over the wheel to caliper 2?

Yes, absolutely.

[Davie_GLA]

Just been out on the bike and there is plenty of stopping power available, just feels a little soft.

There is absolutely no room for a radial MC though with the standard switch gear.