hippyracer Posted October 8, 2017 Share Posted October 8, 2017 Hello Guys It's been a while since I've been on here and I hope you are all well. I'm hoping you can help me on this one because I'm stumped. Bled my rear brake and put new pads in on my MT09, made sure there is no air in the system and pads are seated correctly. As soon as I bolt calliper back on to mount I loose pressure (rear brake doesn't work) but when I unbolt calliper and just rest it on the disc it works perfectly. I've checked for leaks but can't see anything and the piston and piston seal are fine. Any help will be much appreciated. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted October 8, 2017 Moderator Share Posted October 8, 2017 Have you checked the sliders are free (I'm thinking not) as that is one ugly ass design of caliper, everything out there to corrode and stick. If you say they are perfect too, (something isn't because its not working) what happens if you put the caliper on the disk in whatever way you suggest it works perfectly and then just move it to line up with the bolts and tighten up. Link to comment Share on other sites More sharing options...
slice Posted October 8, 2017 Share Posted October 8, 2017 As Cynic said got to be something sticking or jammed when you offer it up, best bet, take it apart again and re-do it grease and clean everything and check for trapped connectors or anything out of line. Link to comment Share on other sites More sharing options...
hippyracer Posted October 8, 2017 Author Share Posted October 8, 2017 I have taken it apart a couple of times, re-cleaned and re-greased but still no luck. I can't make out why when the calliper is not bolted to mount/slider and just resting on the disc it works perfectly. Link to comment Share on other sites More sharing options...
Variomatic Posted October 8, 2017 Share Posted October 8, 2017 Have you checked that you haven't kinked the line? Perhaps when you let it sit loosely it's not kinked, but once you bolt it down it flexes the line and crimps it closed, worth checking that. Something is clearly shifting when you bolt it down, and whatever it is it's got to be quite severe to stop hydraulics from moving. Stupid question but have you checked you actually assembled everything correctly? It's easy to miss a fuckup when you throw everything back together quickly, god knows I've done that before. Link to comment Share on other sites More sharing options...
hippyracer Posted October 8, 2017 Author Share Posted October 8, 2017 Hello Variomatic I put everything thing back as it should be I even watched a couple of youtube videos to make sure I was doing it right. I've ordered a new braided hose, hopefully that will sort it. Thank you for the help though. Link to comment Share on other sites More sharing options...
slice Posted October 8, 2017 Share Posted October 8, 2017 Just thinking out loud here but you haven't got the connector the wrong way round have you? Cos that will stress the line closed when you tighten it up. The middle one of these is the usual connector on most bikes and they can be fitted the wrong way round i.e. connector pipe inwards not outwards. Link to comment Share on other sites More sharing options...
hippyracer Posted October 8, 2017 Author Share Posted October 8, 2017 Hello Slice I didn't dismantle the hose. All I done was release calliper from its holding mount, changed the pads, bolted calliper back onto the mount and bled the brake. Link to comment Share on other sites More sharing options...
Moderator Cynic Posted October 8, 2017 Moderator Share Posted October 8, 2017 Nope, wont be the hose. You say it works perfectly when you just put it on the disk but nothing when you bolt it up. Are you allowing the caliper to locate properly. When you refit that caliper the piston may well be sitting against the pad, against the disk. The caliper its self is holding the rear pad and that will take the pressure of several complete movements of the brake pedal to take up the slack and give a proper pedal pressure. Link to comment Share on other sites More sharing options...
hippyracer Posted October 8, 2017 Author Share Posted October 8, 2017 Hello Cynic I've pumped the pedal more than 20 times to take up the slack but still no luck. I would just like to say thank you for the help guys, it's much appreciated. Link to comment Share on other sites More sharing options...
jimmy Posted October 8, 2017 Share Posted October 8, 2017 Can you post a video that way we can see the issue. Post it direct or via a link to the Tube Link to comment Share on other sites More sharing options...
Moderator Cynic Posted October 8, 2017 Moderator Share Posted October 8, 2017 Could be the m/c, did have the same thing on my daughters bike. Still don't think its the hose. Link to comment Share on other sites More sharing options...
hippyracer Posted October 8, 2017 Author Share Posted October 8, 2017 Hello Jimmy. i'll post a video tomorrow. Link to comment Share on other sites More sharing options...
Tommy xs Posted October 8, 2017 Share Posted October 8, 2017 I had a terrible time bleeding my xjr rear brake till I realized the caliper has two bleed nipples but that's not going to help you if it is working till you mount it, all I can think is a twist in the line as verio has already suggested. Link to comment Share on other sites More sharing options...
Variomatic Posted October 10, 2017 Share Posted October 10, 2017 Only possible solution I can think of is either a kinked line when you bolt everything down, or maybe a metric fuck load of air in the line, all I can think is bleed it again paying particular attention to making sure their is always enough fluid in the reservoir. Sometimes breaks can be a complete bastard, but I don't see any reason they shouldn't have pressure when lose as opposed to bolted down. Link to comment Share on other sites More sharing options...
hippyracer Posted October 10, 2017 Author Share Posted October 10, 2017 Found the cause, there was a slight leek around the bleed nipple so I've ordered a new one and I thought I would treat my MT09 to some Hel Braided hoses in the process. Once again guys, thank you for all your help...it's much appreciated. 1 Link to comment Share on other sites More sharing options...
Moderator drewpy Posted October 12, 2017 Moderator Share Posted October 12, 2017 On 10/10/2017 at 8:50 PM, hippyracer said: Found the cause, there was a slight leek around the bleed nipple those pesky vegetables again! 1 Link to comment Share on other sites More sharing options...
neversaydie Posted October 12, 2017 Share Posted October 12, 2017 8 hours ago, drewpy said: those pesky vegetables again! Lettuce hope hes' solved the problem 2 Link to comment Share on other sites More sharing options...
hippyracer Posted October 12, 2017 Author Share Posted October 12, 2017 Update: Received new hel performance braided hose and bleed nipple. Once I fitted new parts and bled the system I was hoping that would be the end of it, well I was wrong on that one. When I rode my bike home I still found that I had a small leak around the bleed nipple area of the calliper. What I noticed when I removed the old bleed nipple it was rusted at the end of it (which is a bit worrying). I'm thinking when I removed the old nipple and where it has rusted it has pitted the internal thread causing it to leak. So now I have decided to get a 2nd hand calliper from eBay. Lettuce hope this put this to bed once and for all. 1 Link to comment Share on other sites More sharing options...
Simon46 Posted October 12, 2017 Share Posted October 12, 2017 I have to bleed my xt rear caliper this weekend. Im going to hang it from the ceiling by its front wheel. The bubbles just wont go. 1 Link to comment Share on other sites More sharing options...
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