leggins Posted June 22, 2006 Report Share Posted June 22, 2006 Im just buying a 250 rev 3 from a dealer.While taking a test drive I noticed the rear brake was non existant. I pointed this out to the mechanic who said he would see to it. He said he had done all the usual things i.e bleed ,clean calipers etc . At this time he thought he had it sorted ( 80% ) Another road test and they went again compeletly. There is no sign of leakage. Can anyone help this poor frustrated man cheers leggins Quote Link to comment Share on other sites More sharing options...
alan bechard Posted June 22, 2006 Report Share Posted June 22, 2006 Bleed, Bleed and uh, bleed again. Quote Link to comment Share on other sites More sharing options...
coxy Posted June 22, 2006 Report Share Posted June 22, 2006 there may be a problem with the master cylinder or the bolt holding the back brake onto the pipe may be tightened too tight this is the problem i had with my old gasser and it did exactly the same loosened the bolt off a tiny bit and it was fine afta that Quote Link to comment Share on other sites More sharing options...
jordi Posted June 22, 2006 Report Share Posted June 22, 2006 Try new seals in the master cylinder, cheap enough from a dealer. Quote Link to comment Share on other sites More sharing options...
barrybaines Posted June 22, 2006 Report Share Posted June 22, 2006 I had exactley the same problem with my 04 rev 3 after changing all seals and making sure everthing was immaculately clean I gave up hope and went on holiday leaving the bike in my old mans capable hands. On return he tells me he just bled it like another 7-8 reservoirs full and so far so good! There must be an amazing hiding place for air in that brake system somewhere! Quote Link to comment Share on other sites More sharing options...
barrybaines Posted June 22, 2006 Report Share Posted June 22, 2006 You told me you did it!!!! well I done all the donkey work just anoyed me and when I got back he done it for me after all it is at his house! Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted June 23, 2006 Report Share Posted June 23, 2006 I bet you guys are still bleeding the traditional way??? If you reverse bleed it, (inject the brake fluid in with a syringe from the calliper)...it will take about 1 min. and it will be fine. Always works really well for me. Quote Link to comment Share on other sites More sharing options...
ausy300pro Posted June 23, 2006 Report Share Posted June 23, 2006 In my experience, you sometimes get air stuck behind pistons in caliper, I always make sure pistons are all the way back into caliper, it then bleeds up easily, one other thing that does give the problem you have, is when seals are leaking in caliper, you usually find a little drag from brake as well, this is because instead of pistons being drawn back into caliper air is drawn in down side of seals, a way of getting last bit of air out when brakes are already bled is to jam lever down as hard as possible and leave over night this allows any remaining air to find its way back up to the highest point, hopefully the reservoir, easier to do with front brake just cable tie lever back to bars. Quote Link to comment Share on other sites More sharing options...
barrybaines Posted June 23, 2006 Report Share Posted June 23, 2006 I bet you guys are still bleeding the traditional way???If you reverse bleed it, (inject the brake fluid in with a syringe from the calliper)...it will take about 1 min. and it will be fine. Always works really well for me. Done that a few times thats why I got pee`d off! a way of getting last bit of air out when brakes are already bled is to jam lever down as hard as possible and leave over night this allows any remaining air to find its way back up to the highest point done this also I think my bike just wanted a little rest from my abuse!!!! Quote Link to comment Share on other sites More sharing options...
alan bechard Posted June 23, 2006 Report Share Posted June 23, 2006 I have been having fairly good success lately by back bleeding. What I do, is hook up to back bleed with a large syringe I have, then while applying pressure, I crack the line on the caliper and look for clear fluid to drain off, then I crack the line on the master, and again wait for clear fluid to drain off then continue backfilling till I bring my resovoir up to the proper level. (I start with it empty) This works easily on the Sherco's as the line bolts are accessible with the master etc mounted. Last Beta I did, I believe that we had to take something loose to get access or put everything in the proper orientation for good bleeding (fluid low, air high) Quote Link to comment Share on other sites More sharing options...
leggins Posted June 23, 2006 Author Report Share Posted June 23, 2006 first of all many thanks for all your help and valid advice. Today I visited a very happy mechanic. After lots of head scratching this chap gave in and called beta for advice. After a long explanation He was told that the problem was the master cyclinder had major wear . I know it seems hard to believe that the rubber seals would outlast a aluminium cyclinder but this is a common fault. A new master cyclinder is on its way from the dealer, Problem solved.........I will let you know. many thanks Leggins Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted June 23, 2006 Report Share Posted June 23, 2006 What did you get peed off with Barry???..back bleeding is SO easy...if you want, I;ll do yours next time I see you at Kilkenny...trust me..it'll take about 2 mins! I used to do my Betas about every couple of months like that. Kept the brakes real nice Quote Link to comment Share on other sites More sharing options...
barrybaines Posted June 23, 2006 Report Share Posted June 23, 2006 What did you get peed off with Barry???..back bleeding is SO easy...if you want, I;ll do yours next time I see you at Kilkenny...trust me..it'll take about 2 mins!I used to do my Betas about every couple of months like that. Kept the brakes real nice Would`ve been great I agree but you can ask Heath the bloody thing would last just over an hour then that illussive air bubble would wake up!!! I don`t think the author of this topic is in new master cylinder situation yet but hey! Hope it works mate P.S Stu you got a bike lined up yet? Quote Link to comment Share on other sites More sharing options...
stuessenhigh Posted June 24, 2006 Report Share Posted June 24, 2006 Nope...starting to get bored of the Aprilia now too!!...although, in a strange way I think its helping my riding. So...let me know if you wanna sell yours!! Quote Link to comment Share on other sites More sharing options...
neonsurge Posted June 24, 2006 Report Share Posted June 24, 2006 first of all many thanks for all your help and valid advice. Today I visited a very happy mechanic. After lots of head scratching this chap gave in and called beta for advice. After a long explanation He was told that the problem was the master cyclinder had major wear . I know it seems hard to believe that the rubber seals would outlast a aluminium cyclinder but this is a common fault. A new master cyclinder is on its way from the dealer, Problem solved.........I will let you know. Yup, I had the same thing with my '03. Tried everything including replacing the cylinder seals after reading about r2w's problems but still couldn't get much of a rear brake. In the end I bit the bullet, bought a new master cylinder ( Quote Link to comment Share on other sites More sharing options...
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.