Fire3500 Posted January 25, 2017 Share Posted January 25, 2017 I'm going to have to beg a bit of expertise from you folks... I've got an issue that doesn't seem to be progressing. Bike: 1985 GSX-R 750 F Issue: front brake, cannot get a decent lever, lever comes back to bars, will not improve with repeated pumping Already done: strip and clean callipers, strip and clean master cylinder, new seals in callipers, new seals in master cylinder, new HEL lines (bypassing connector union as simple is good, right?), new correct spec brake fluid. So the front brakes have been completely stripped and cleaned and re-sealed. New lines and bled up seemingly correctly however the lever comes back to the bars and the brake effort is compromised by this. The lever is not bent and the bore/cylinders of the callipers and master cylinder looked all OK. The weird thing is that when attached to the fork legs and biting on the disks you get this crap lever, but if you unbolt the callipers from the fork legs and let them just "float" then you get a great lever that you'd feel confident to ride with. I'm pulling my hair out over this one, anyone any ideas? Cheers! Quote Link to comment
paulo66 Posted January 25, 2017 Share Posted January 25, 2017 hi have you tried bleeding the master cylinder, you might have an air lock there Quote Link to comment
sharpy Posted January 25, 2017 Share Posted January 25, 2017 Lazy way is to park bike on side stand leave it parked like that all nite with the brake lever strapped up against the throttle tube. Have handle bars turned to the left so all the air flaots to the surface.. works wonders sometimes. But yes, always get good pressure at the master cylinder 1st when doing brakes. then work ure way down the line bleeding each connection. 1 Quote Link to comment
jameskat Posted January 25, 2017 Share Posted January 25, 2017 If it gets a good lever pull when not bolted on then it could be something is not inline and is causing the disc to twist, so when the lever is released it pushed the pistons back to far and thus the lever coming back to the bar. 3 Quote Link to comment
TLRS Posted January 25, 2017 Share Posted January 25, 2017 I'm with mr kat, makes the most sense from your story! 1 Quote Link to comment
Captain Chaos Posted January 25, 2017 Share Posted January 25, 2017 11 hours ago, Fire3500 said: The weird thing is that when attached to the fork legs and biting on the disks you get this crap lever, but if you unbolt the callipers from the fork legs and let them just "float" then you get a great lever sounds like a bent disc or two, just like what the two previous posts say. Quote Link to comment
HDTboy Posted January 26, 2017 Share Posted January 26, 2017 How worn are your discs? New discs helped to improve mine. The brakes are generally not good though Quote Link to comment
Jonny Posted January 28, 2017 Share Posted January 28, 2017 On 26/01/2017 at 3:05 AM, HDTboy said: How worn are your discs? New discs helped to improve mine. The brakes are generally not good though This is true. You only need 0.5mm of wear on these discs to send it right off as they are quite thin to start with. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.