k3lv Posted February 7 Share Posted February 7 Hi folks , so I have a 1999 gsxr 750 on mot it had advisory for "insufficient lever travel" on the the front brake ....so rebuilt the calipers,put new braided lines on today .....and still the same ,can pull the lever to the bar , the braking force is fantastic and the lever is firm ....but just not firm enough....any ideas ? Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 7 Share Posted February 7 (edited) fresh fluid and master cylinder rebuild kit. Edited February 7 by RideWithStyles 1 Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 7 Author Share Posted February 7 24 minutes ago, RideWithStyles said: fresh fluid and master cylinder rebuild kit. Yeah all new fluid in today ......got a MC rebuild kit on order just incase , was really hoping the new lines would solve it as the bike had the original brake hoses on Quote Link to comment Share on other sites More sharing options...
husoi Posted February 7 Share Posted February 7 Can't see what is the problem with a short travel of the break lever. If the pads are new it is evident the travel distance of the lever is less than when they are near worn stage. My pan does that and never heard anybody telling me that to be a problem. Is the guy trying to make some extra quid? 1 Quote Link to comment Share on other sites More sharing options...
Nick the wanderer Posted February 7 Share Posted February 7 A bit confusing when it says insufficient travel but really means too much travel. Master Cylinder rebuild kit as has been suggested is the only thing left. Short of bleeding it again and again, l hate bleeding bike brakes, l always struggle.. 2 Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 7 Author Share Posted February 7 Yeah it got me at first , but means the lever can be pulled to the bar , gonna try re bleeding while I wait for parts.... , thanks for the replies , Quote Link to comment Share on other sites More sharing options...
husoi Posted February 7 Share Posted February 7 Not sure about the GSX's I run into some trouble bleeding the brakes on the Shadow The issue with it was a air bubble sitting in the master cylinder. The only way to get rid of it was to remove the master cylinder and reservoir and tilt it to make the air bubble to escape to the reservoir. Once that was done the breaks were fine. Quote Link to comment Share on other sites More sharing options...
Ian Frog Posted February 7 Share Posted February 7 I know you have probably tried it but leave it overnight with the lever held pulled in to the bars with a strap or tie of some kind and then see if it is better in the morning, sometimes this can encourage stubborn air bubbles to move. Sorry for stating the obvious if you have already thought of it. Cheers Ian 2 1 Quote Link to comment Share on other sites More sharing options...
Stu Posted February 7 Share Posted February 7 has it had the lever replaced at any point? 1 Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 8 Share Posted February 8 (edited) suzuki master cylinders have always been the weakest part of there bikes up until the last couple of years. they say its designed for feel...ok ish when factory fresh for the first service but down hill after that... yes a perfect bleed is necessary. oh did you replace and sealed the bleed nipples thread? these shouldnt be the toc 6pot callipers, hopefully not. Edited February 8 by RideWithStyles correction 2 Quote Link to comment Share on other sites More sharing options...
Ian Frog Posted February 8 Share Posted February 8 Oh good grief yes Toc 6 pots Arrgh ! ask anyone who has ridden a Busa! Awful brakes best replaced with Triumph 2 pots or similar, strangely enough the calipers work fine on my ZRX which probably backs up the comments about Suzuki master cylinders. Cheers Ian 1 Quote Link to comment Share on other sites More sharing options...
Stu Posted February 8 Share Posted February 8 9 hours ago, Ian Frog said: Oh good grief yes Toc 6 pots Arrgh ! ask anyone who has ridden a Busa! Awful brakes best replaced with Triumph 2 pots or similar, strangely enough the calipers work fine on my ZRX which probably backs up the comments about Suzuki master cylinders. Cheers Ian Or anything with Tokico 4 or 6 pots! I replaced mine on the TL with Nissin calipers! I didn't have to rebuild those every year Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 15 Author Share Posted February 15 (edited) Thanks for the replies so today was new MC rebuild kit,new caliper seals,new lines,new bolts and washers all round new bleed nipples and 1lt fresh brake fluid ......can still pull the lever to the bar ....there's a little more pressure but that's all , also pushed the pistons back and the fluid that came into the fluid reservoir smelt like absolute ass , .....anyone know a good straight swap caliper ? I've never known anything like these ..... infuriating Edited February 15 by k3lv Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 15 Author Share Posted February 15 On 07/02/2024 at 22:16, Stu said: has it had the lever replaced at any point? The actual lever .......no I can't say it has Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 15 Share Posted February 15 (edited) thought you said youd changed the fluid, cleaned calipers (inside and out) so that cant smell if youve sont that well enough, bleed the brakes, mc kit making sure the shaft seal is facing the correct way??? have you recently checked for air again? and do it after a ride..... what setting is the lever position if it has? only few things left is to properly bleed the brakes.....vacuum kits are very good for it. one last thing, when you lift the res cap is the rubber seal there, is it flatish or full on top hat suck out each time youve checked? other than that it gets expensive changing the master cylinder, brembo do sell their after market versions but this is getting to serious money. calipers you choices maybe limited than you hope. Edited February 15 by RideWithStyles autocorrect Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 15 Author Share Posted February 15 40 minutes ago, RideWithStyles said: thought you said youd changed the fluid, cleaned calipers (inside and out) so that cant smell if youve sont that well enough, bleed the brakes, mc kit making sure the shaft seal is facing the correct way??? have you recently checked for air again? and do it after a ride..... what setting is the lever position if it has? only few things left is to properly bleed the brakes.....vacuum kits are very good for it. one last thing, when you lift the res cap is the rubber seal there, is it flatish or full on top hat suck out each time youve checked? other than that it gets expensive changing the master cylinder, brembo do sell their after market versions but this is getting to serious money. calipers you choices maybe limited than you hope. Yeah everything is the correct way , I've tried a vacuum bleeder , I've tried all types of bleeders , it's had 2 litres of fluid through now , tried the "tie the lever to the bar" trick .........I think I'll just swap them out Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 15 Share Posted February 15 Hello Brembo id like the Toprack spec please..... 1 Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 15 Author Share Posted February 15 14 minutes ago, RideWithStyles said: Hello Brembo id like the Toprack spec please..... Yeah think I'm definitely gonna swap them out...but ......also want to find out what's going on everything is as it should be , maybe I have dodgy fluid or something because it went bad real fast , just running it through a clean system made it 4 shades darker easily lol Quote Link to comment Share on other sites More sharing options...
Nick the wanderer Posted February 15 Share Posted February 15 If the fluid is getting dirty when bleeding there must be dirt in there somewhere. A trapped corner of crap hiding in one of the corners. Did you strip the calipers pistons out job? Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 15 Author Share Posted February 15 27 minutes ago, Nick the wanderer said: If the fluid is getting dirty when bleeding there must be dirt in there somewhere. A trapped corner of crap hiding in one of the corners. Did you strip the calipers pistons out job? Yeah last month i replaced all the piston seals and dust seals, gave it a clean .....wasn't super thorough as it was pretty clean in there. Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 15 Share Posted February 15 (edited) nope not dodgy fluid - thats why you havent actually clean them enough INSIDE, their will be pockets of dark jelly hiding in the corners of the caliper and MC that is being flushed/mixed with the fresh. now this wont be soley down the the longer throw of the lever but certainly will degrade the fluid far faster. with this aspect comes to light have you actually over looked anything?? cos if you have to keep bleeding the system youve got a very tiny leak, enough to let air in but not enough to let fluid out (hopefully. if its not quite sealed /de aired enough it can give a longer throw as your compressing small pockets of air and not fluid. Edited February 16 by RideWithStyles Quote Link to comment Share on other sites More sharing options...
husoi Posted February 16 Share Posted February 16 If you dismantle the calipers to service the pistons you should have replaced the fluid completely. For the sound of it you left the old fluid in the brake line which by now have contaminated the new one. My advice. get the calipers apart (again) give it a clean (again) Clean (and service if not done yet) the master cylinder This for front and rear wheels. Luckily you don't have a CBS so this is not too hard to do. Personally I always replace the break fluid with methylated alcohol to give the lines a good clean and then add the new fluid until all is clear and air free. Depending on the master cylinder shape, it's possible that you will have to turn it in a way that the air trapped in the banjo will go to the reservoir to remove any air from the system. as said before, some times leaving it over night allows air to go all the ay up and go to the reservoir or stay trapped in the upper banjo. In case you're wondering, banjo is the connector at the end of the brake line Repairs on motorbikes always follow the principle that you do it cheap and you will do it twice... 1 Quote Link to comment Share on other sites More sharing options...
RideWithStyles Posted February 16 Share Posted February 16 if you fook it up its trice. 2 Quote Link to comment Share on other sites More sharing options...
S-Westerly Posted February 16 Share Posted February 16 Which is why I who have the mechanical ability of a chimpanzee pay someone else to do it for me. The someone else's being professional motorcycle mechanics with many years of experience. 1 1 Quote Link to comment Share on other sites More sharing options...
k3lv Posted February 16 Author Share Posted February 16 Well I figured where the dirty fluid came from ......I put an old caliper on that wasn't given to me by a mate that just had lying around .....feel like a right ass ....bit ah well gonna clear out all the lines and try again with the correct caliper today lol 2 1 Quote Link to comment Share on other sites More sharing options...
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