trialsmax04 Posted September 5, 2010 Report Share Posted September 5, 2010 trying to fix a mates magura, (04 style) and the symptoms are lazy pistons. On closer inspection it was in fact the master cylender piston that was stuck. Now after removing and cleaning the piston wont go back into the bore. After a phone call to tarty apparently the pistons can swell slightly when out of the bore. so i have tried the working piston out of an old brake of mine and that went in, all beit rather tightly. Now ive come back to it it is insanely tight much like the original. 2 pistons swelled or is it a fecked lever body? max Quote Link to comment Share on other sites More sharing options...
Revolver Posted September 5, 2010 Report Share Posted September 5, 2010 Did you clean out the inside of the cylinder too? I think you can sand down the seal, but I'd be very careful, else it'll just leak. Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 5, 2010 Author Report Share Posted September 5, 2010 tried to but i dont understand how a perfectly good magura can go gay like that? Quote Link to comment Share on other sites More sharing options...
Alex Dark Posted September 5, 2010 Report Share Posted September 5, 2010 Sand the piston with some 320 grit...after taking the o-ring off until it fits in the bore. Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 5, 2010 Author Report Share Posted September 5, 2010 Will try later, alex come on msn ..... Quote Link to comment Share on other sites More sharing options...
Matt Burrows Posted September 5, 2010 Report Share Posted September 5, 2010 Sand the piston with some 320 grit...after taking the o-ring off until it fits in the bore. That won't help if the seal has swelled up though... Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 6, 2010 Author Report Share Posted September 6, 2010 In all fairness it is the piston that wont go in. so i will try that this morning.. cheers guys. Quote Link to comment Share on other sites More sharing options...
Matt Burrows Posted September 6, 2010 Report Share Posted September 6, 2010 Take off both the seals and try to fit just the piston. It should slide in quite easy, and obviously if not then sand it till it does. Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 6, 2010 Author Report Share Posted September 6, 2010 Right, Ive taken both seals off and sanded down till the piston slides in the bore happily. There is still room to take it a tad more but ive left it for the moment. Now when i put the o-ring onto the piston its far to tight? Now what? Quote Link to comment Share on other sites More sharing options...
Matt Burrows Posted September 6, 2010 Report Share Posted September 6, 2010 Once the seals have swelled all you can do is replace them. Or lube everything up, rebuild the brake and hope the spring strength is enough to overcome the seal friction. Quote Link to comment Share on other sites More sharing options...
trialsmax04 Posted September 6, 2010 Author Report Share Posted September 6, 2010 fair doos cheers man time for a new piston... Quote Link to comment Share on other sites More sharing options...
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