gazzaecowarrior Posted August 30, 2013 Report Share Posted August 30, 2013 Been having trouble with my rear brake on my 09 250. It just seems to lose braking power the longer I ride. Ive cleaned the disc, pads don't seem contaminated and have 3mm depth. Wheel won't even lock despite it doing so at the start of the ride. I re bled the brake. New fluid. Piston on right side of calliper doesn't seem to want to compress all the way back into calliper when compressed. Left one compresses almost flush with face of inner calliper. Is this normal or should they both slide back into the calliper equally? Disc sits between pads well but it looks like its the left side that's doing most of the work. Any ideas ? Quote Link to comment Share on other sites More sharing options...
jfc Posted August 30, 2013 Report Share Posted August 30, 2013 (edited) If you have adjusted the brake lever and not left a small amount of free play the brake fluid can not return to the master cylinder, this will cause the extra heat created during riding to overheat the fluid because the pads do not release correctly. Once the fluid is hot the brake will fade. Edited August 30, 2013 by jfc Quote Link to comment Share on other sites More sharing options...
gazzaecowarrior Posted August 30, 2013 Author Report Share Posted August 30, 2013 If you have adjusted the brake lever and not left a small amount of free play the brake fluid can not return to the master cylinder, this will cause the extra heat created during riding to overheat the fluid because the pads do not release correctly. Once the fluid is hot the brake will fade. Thanks for that information. Pedal was set correctly and plenty of space left in resevoir so I'm not sure its that. What do you think about the pistons ? Should they retract equally into the caliper ? Quote Link to comment Share on other sites More sharing options...
tltel Posted August 30, 2013 Report Share Posted August 30, 2013 Pistons should normally have same amount of travel and would normally compress flush to calliper body. Sounds like one piston is doing all the work. I would get a seal and piston kit, strip it out and rebuild. Also sounds like you have some air trapped. TLTEL Quote Link to comment Share on other sites More sharing options...
gazzaecowarrior Posted August 30, 2013 Author Report Share Posted August 30, 2013 Pistons should normally have same amount of travel and would normally compress flush to calliper body. Sounds like one piston is doing all the work. I would get a seal and piston kit, strip it out and rebuild. Also sounds like you have some air trapped. TLTEL I think the same. Will do just that. Thanks Quote Link to comment Share on other sites More sharing options...
gazzaecowarrior Posted August 31, 2013 Author Report Share Posted August 31, 2013 Oh my god. Just priced up the cost of caliper kit and master cylinder kit and it is £45. Quote Link to comment Share on other sites More sharing options...
gazzaecowarrior Posted August 31, 2013 Author Report Share Posted August 31, 2013 Anybody know what size torque socket fits the two bolts on the rear calliper ? Ive just ordered some torque keys and am just hoping one of them fits. Why aren't they just hex head ? Quote Link to comment Share on other sites More sharing options...
gazzaecowarrior Posted August 31, 2013 Author Report Share Posted August 31, 2013 Been speaking to one of my trials mates who says the 09 models suffered from caliper failure. The symptoms of which sound exactly like mine i.e. Gradual loss of braking during the ride. Lampkins typically replaced his. Quote Link to comment Share on other sites More sharing options...
betabonkers Posted August 31, 2013 Report Share Posted August 31, 2013 Been speaking to one of my trials mates who says the 09 models suffered from caliper failure. The symptoms of which sound exactly like mine i.e. Gradual loss of braking during the ride. Lampkins typically replaced his. It's a hard job being right all the time, I suppose someone has to be though Quote Link to comment Share on other sites More sharing options...
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