paulw Posted December 17, 2008 Report Share Posted December 17, 2008 Hi All, Basically the bike is a 2001 315 and the rear caliper was butchered by my mate when the bleed nipple snapped off so i had to buy a brand new caliper (that will teach me to give it to somone who knows what there doing rather than mess it up myself) anyway after new caliper was fitted i started to try and bleed the thing and well its been a nightmare ive tried syringe method's gravity methods and a pressure sucker thing you connect to the airline and nadda it just wont seem to bleed ive tried this for weeks on and off when ive had the time and well id like to use the bike at some point so anyone have any idea's The syringe method basically backfilling the system is what ive been told by a few is the best way because of the new caliper however it seems to get to a point and then wont push in anymore if i do push even harder the pipe eventually flys off and coats everything in brake fluid its like there is a blockage or somthing but where? Quote Link to comment Share on other sites More sharing options...
graeme17 Posted December 17, 2008 Report Share Posted December 17, 2008 I have had a similar problem previously on my Beta. It turned out there was insufficient travel on the master cylinder/brake pedal side of the system. To overcome this I removed the rear master cylinder from the frame and brake pedal and used a suitable implement to operate the master cylinder to achieve full strokes of the inner plunger whilst a friend operated the bleed nipple on the caliper. Bled no problem after that hope this helps Quote Link to comment Share on other sites More sharing options...
slapshot 3 Posted December 17, 2008 Report Share Posted December 17, 2008 I have had a similar problem previously on my Beta.It turned out there was insufficient travel on the master cylinder/brake pedal side of the system. To overcome this I removed the rear master cylinder from the frame and brake pedal and used a suitable implement to operate the master cylinder to achieve full strokes of the inner plunger whilst a friend operated the bleed nipple on the caliper. Bled no problem after that hope this helps Try taking the actuation lever off and then bolting the Master cylinder back into the frame. Long screwdriver or any other implement (a non-scoring piece of plastic would be perfect) to pump the cylinder but be gentle you could score the barel of the master cylinder doing this. Graeme... did you manage to keep a straight face writing all that Quote Link to comment Share on other sites More sharing options...
greg Posted December 17, 2008 Report Share Posted December 17, 2008 the bleed nipple sheared on my gasser recently,took it to a local (doncaster) engineering firm ,they drilled out nipple rethreaded it 1mm bigger and up to now its sound, Quote Link to comment Share on other sites More sharing options...
paulw Posted December 17, 2008 Author Report Share Posted December 17, 2008 I shall give this a go tommorow thanks for the idea Quote Link to comment Share on other sites More sharing options...
paulw Posted December 17, 2008 Author Report Share Posted December 17, 2008 the bleed nipple sheared on my gasser recently,took it to a local (doncaster) engineering firm ,they drilled out nipple rethreaded it 1mm bigger and up to now its sound, Quote Link to comment Share on other sites More sharing options...
paulw Posted December 18, 2008 Author Report Share Posted December 18, 2008 Well I didnt wait till tommorow and im still no further forward i took off the stuff as suggested and it may be a little firmer possibly or i may have just pumped it so many times that ive lost feeling but basically still no back brake so tommorow i think im going to buy a large hammer and beat the hell out of it because its really anoying me now! the master cylinder is doing somthing because there is some fluid/air coming out some of the time when i pump it but it seems like it just never bleeds i cant understand why it wouldnt back bleed any ideas why it might not ? is there somthing in the master cylinder that wont allow fluid back maybe ? tommorow is a new day ill be less tired and ill give it another go so keep them ideas coming please Quote Link to comment Share on other sites More sharing options...
stork955 Posted December 18, 2008 Report Share Posted December 18, 2008 Gday, check out the "Rev 3 Rear Brake Problem" thread over in the Beta section. Sorry I dunno how to post thread links. There may be some stuff there to help you out. Cheers, Stork. Quote Link to comment Share on other sites More sharing options...
graeme17 Posted December 18, 2008 Report Share Posted December 18, 2008 Graeme... did you manage to keep a straight face writing all that Double entendre.........moi? pas du tout!!! Quote Link to comment Share on other sites More sharing options...
paulw Posted December 18, 2008 Author Report Share Posted December 18, 2008 ok so ive been through the beta thread aswell and well im convinced there is no air in the system but im also convinced for whatever reason? the pumping of the pedal simply isnt moving the pistons out enough the pistons are moving ok when you pump the pedal but simply dont seem to come out far enough if that makes sense? any ideas? can someone suggest a good starting point with the rod on the master cylinder or someone with a 315 tell me how many visable threads they have so i can make sure mine is ok? ive moved it up and down but still no joy really Quote Link to comment Share on other sites More sharing options...
graeme17 Posted December 18, 2008 Report Share Posted December 18, 2008 can someone suggest a good starting point with the rod on the master cylinder or someone with a 315 tell me how many visable threads they have so i can make sure mine is ok? ive moved it up and down but still no joy really Did you try removing the rod and pedal.. When the pedal is attached there is a limitation on the travel of the master cylinder inner plunger. Depending on how much air is in the system the volume of the master cylinder side of the rear brake with the restricted travel mentioned previously is not sufficient to prime the caliper. However one of the seals on the master cylinder may now be damaged with all the pumping!! It could be worth removing the master cylinder inner plunger to check all is well to prevent further vexation. Best of luck Quote Link to comment Share on other sites More sharing options...
paulw Posted December 18, 2008 Author Report Share Posted December 18, 2008 Did you try removing the rod and pedal..When the pedal is attached there is a limitation on the travel of the master cylinder inner plunger. Depending on how much air is in the system the volume of the master cylinder side of the rear brake with the restricted travel mentioned previously is not sufficient to prime the caliper. However one of the seals on the master cylinder may now be damaged with all the pumping!! It could be worth removing the master cylinder inner plunger to check all is well to prevent further vexation. Best of luck Yes the rod and pedal have been off and seem ok the master cylinder seems to be pumping its just like it isnt shifting enough to make the pistons come out far enough for example without pads in front of them the pistons should move out farther and farther untill the piston pops out but it doesnt it simply moves slightly out and then back in again if that makes sense Quote Link to comment Share on other sites More sharing options...
dad- Posted December 18, 2008 Report Share Posted December 18, 2008 had the same problem with ralphs 4rt. its air trapped in the top of the master cylinder. try pushing master cylinder piston up and down a few times using a screwdriver and hold the pressure then undo banjo bolt that holds rear brake hose to master cylinder. repeat this a few times then bleed through to rear caliper as normal. hope this helps Quote Link to comment Share on other sites More sharing options...
copemech Posted December 19, 2008 Report Share Posted December 19, 2008 As Dad said! Quote Link to comment Share on other sites More sharing options...
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