Cookiemonster Posted September 12, 2013 Report Share Posted September 12, 2013 whilst the carb was off my 07 scorpa the rear brake reservior was put in the correct place via the bracket on the carb (previously it was zip tied on a pipe) anyway the reservoir wasn't that full & as it was now at an angle after riding last Saturday the pressure on the pedal went, my fault I know so I've back bled brakes & clutches using a syringe & hose many times on previous bikes, Montesa & KTM with no problems but can't get it right after 3 hours trying tonight! about 6 months ago I changed the rear brake pads, refitted the rear wheel & back bled the rear brake via the bleed nipple in no time at all so I'm at a loss this is what I've tried so far removed reservior cap, attached syringe & hose to bleed nipple, opened up bleed nipple a 1/4 turn, pressed the syringe & nothing happens, apply a little more pressure & still nothing, apply more pressure & fluid starts to come out of the syringe were it meets the hose there doesn't seem to be any leaks elsewhere in the system, I've cleaned the areas around the pipes & master cylinder & can't see any leaks tried the above but opened the banjo bolt as well (on the caliper only) & all this did was leak fluid through the banjo bolt feels like it's not letting the fluid from the syringe into the system, had something similar to this on a Montesa clutch once but when I adjusted the lever it sort of released & I could bleed the clutch easy, as far as I know there is nothing I could do like this to the rear brake will try pushing fluid down hose after taking off reservior tomorrow as per some previous posts so any help you lads can provide might get it sorted in time for me to get out this Saturday thanks Quote Link to comment Share on other sites More sharing options...
jfc Posted September 12, 2013 Report Share Posted September 12, 2013 Have you got any free play at the lever, if not you will not be able to back bleed. Quote Link to comment Share on other sites More sharing options...
nelly1 Posted September 12, 2013 Report Share Posted September 12, 2013 is the nipple blocked Quote Link to comment Share on other sites More sharing options...
tltel Posted September 12, 2013 Report Share Posted September 12, 2013 If you can't back bleed it from the nipple it usually means the hole in the nipple is blocked with dirt, (remove it and clean out with a piece of wire) or the pedal arm has no clearance at the master cylinder or the piston is stuck, jambed or spring is broken. I am surprised that a low fluid would cause brake to fail during one ride, there is not much fluid movement when pedal is pressed. I am thinking master cylinder failure... TLTEL Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 12, 2013 Author Report Share Posted September 12, 2013 cleaned the nipple with wire & there is plenty of free play on the pedal, the piston in the master cylinder moves freely using the pedal & if you push it with your finger when the reservoir was zip tied it was more or less parallel to the ground, now that it's atached to the carb it tilts about 30' & as it was low I think it's drawn some air into it perhaps thanks Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 12, 2013 Author Report Share Posted September 12, 2013 TLTEL what do you mean by 'the pedal arm has no clearance at the master cylinder'? Quote Link to comment Share on other sites More sharing options...
tltel Posted September 12, 2013 Report Share Posted September 12, 2013 hi. I just meant free play, as you just mentioned. I Think I would remove the reservoir pipe from master cylinder and try pushing fluid through that way, maybe try with banjo and nipple on calliper loosened at first . I have bled them this way before. If you still cant push fluid through, its a strip down of the master cylinder, dirt or a broken seal blocking a hole. TLTEL Quote Link to comment Share on other sites More sharing options...
breagh Posted September 13, 2013 Report Share Posted September 13, 2013 (edited) Take the pedal off and use a long Allen key or similar to push the plunger. That way you get full travel. Slacken the bleed nipple and put a short length of clear (just so you can see the air) plastic hose on it pointing upwards and fill with fluid. Plunge away and keep topping the res up. Only problem I've had is a pinhole in the res' pipe. Cheers Edited September 13, 2013 by breagh Quote Link to comment Share on other sites More sharing options...
lineaway Posted September 14, 2013 Report Share Posted September 14, 2013 All above tips are good. I`ve had a few `tough` bikes through the years. Get the rear caliper above the master cylinder. ( hang it with straps or what ever. Just get it high.) Use a long clear line to bleed from caliper nipple. As stated pump without the pedal. If all else fails leave 24 hours to let the air bleed up. Quote Link to comment Share on other sites More sharing options...
tltel Posted September 16, 2013 Report Share Posted September 16, 2013 Did you fix it ?????? TLTEL Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 17, 2013 Author Report Share Posted September 17, 2013 TL TEL not had chance to look at it yet but have this Friday afternoon free thanks to everyone for their advice & as soon as I've fixed it I'll let everyone know how Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 20, 2013 Author Report Share Posted September 20, 2013 hi. I just meant free play, as you just mentioned. I Think I would remove the reservoir pipe from master cylinder and try pushing fluid through that way, maybe try with banjo and nipple on calliper loosened at first . I have bled them this way before. If you still cant push fluid through, its a strip down of the master cylinder, dirt or a broken seal blocking a hole. TLTEL not had chance to look at this yet but have a few more questions TL TEL when you say 'remove the reervoir pipe from the master cylinder & try pushing fluid through that way' do you mean near the r/h side footpeg? I'm just thinking that when you re-attach the pipe you'll have the same problem as there will be air in the pipe between the master cylinder & the reservoir. or do you mean take the pipe of the reservoir & try pushing fluid through that way? thanks, Lee Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 20, 2013 Author Report Share Posted September 20, 2013 Take the pedal off and use a long Allen key or similar to push the plunger. That way you get full travel. Slacken the bleed nipple and put a short length of clear (just so you can see the air) plastic hose on it pointing upwards and fill with fluid. Plunge away and keep topping the res up. Only problem I've had is a pinhole in the res' pipe. Cheers couple of questions before I have a look when you say take the pedal off & use a long allen key to push the plunger you do mean the plunger in the master cylinder? (sorry!) if so when you take the brake pedal off does the plunger rod attached to the pedal just slip out of the master cylinder? or does it stay put & the part I need to plunge is the fork end type piece that attaches the master cylinder to the pedal? if I put a clear length of hose on the slackened bleed nipple & fill it with fluid then open up the reservoir & plunge the master cylinder using an allen key where will the air go? does it just pass through the fluid at the nipple end & thats why I top up the reservoir? thanks for your help, Lee 1 Quote Link to comment Share on other sites More sharing options...
tltel Posted September 20, 2013 Report Share Posted September 20, 2013 Hi. You can do it by just removing the reservoir and putting the syringe on the pipe. I think your first target is to get fluid moving through the system one way or another. The trick if you use a different pipe is to make sure you pre fill the reservoir pipe before refitting, the same goes for any of the hydraulic parts that you dismantle, it can get messy. If you get air in the reservoir pipe it will naturally rise to the reservoir as it is not under pressure. TLTEL Yes the rod will come out with the pedal.. Quote Link to comment Share on other sites More sharing options...
Cookiemonster Posted September 27, 2013 Author Report Share Posted September 27, 2013 bled the brake successfully this afternoon so thanks to everyone for their advice heres how it went for me in case anyone needs advice in the future & also if anyone else wants to give me further advice......... took the pedal off, attached clear hose full of fluid to the bleed nipple & opened nipple (this might not be obvious to some people but It's so you don't have to keep opening & closing the bleed nipple with each stroke of the master cylinder) opended reservoir topped up fluid & started to push the allen key in & out of the master cylinder did this for a while & could see bubbles coming out from the hose on the bleed nipple but I still wasn't getting pressure on the pads I knew it was going to be the hose between the reservoir & the master cylinder as breagh mentioned but looking @ how it was routed I was hoping that it wasn't! took the plunge & took it off to see there were tears near were the hose connects to the master cylinder & the reservoir had some new hose so cut it to length & proceded for at least an hour to try & re route it back to were it should be & once I managed that tried for about another hour to squeeze it onto the master cylinder...... again knew what I had to do but wasn't looking forward to it, so off with the rear mudguard, tank, air box & silencer, took me 10 minutes cut the bad bits off the old hose, reconnected it, refitted the above & 15 minutes later I'm riding up & down the drive & ready to go to Cowm tomorrow!! moral of the story... knew from the start I should have just stripped the bike down & got on with it, would have taken me an hour instead of probably 12 hours over a couple of Fridays, unless that is does anyone knows a smart way to re route hose without removing the above.... thanks again everyone 1 Quote Link to comment Share on other sites More sharing options...
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