martinshaw94 Posted August 28, 2013 Share Posted August 28, 2013 to start with i changed my pads and i had to push the piston in to compensate for the extra pad as they are new but now when i bleed the system to get good pressure but the piston is not moving and fluid is just passing straight through and no pressure is being put onto the piston. i now have no front brake till i get this sorted Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted August 28, 2013 Moderator Share Posted August 28, 2013 Not sure what you mean by "....fluid is just passing straight through..." are you opening and closing the bleed nipple when applying pressure to the lever? Lots of people swear by reverse bleeding it by pushing fluid up from the nipple to the reservior. Link to comment Share on other sites More sharing options...
Ttaskmaster Posted August 28, 2013 Share Posted August 28, 2013 Firstly, check the 'silly mistake' stuff - Is the caliper assembly relatively clean and corrosion-free? Did you snag one of the seals when pushing the pistons back on? Is the existing fluid in the reservoir contaminated? Did you completely flush out the old fluid and/or are you using old brake fluid (which absorbs an alarming amount of water from the air, reducing it's efficiency)? Secondly, more 'silly mistake' if you aren't already familiar with the procedure - are you sure you're bleeding it right? 1/. Close nipple. 2/. Top up fluid. 3/. Pump brake handle a few times, until it starts to get stiff. 4/. Hold brake in tight. 5/. Open nipple until brake goes back against grip. 6/. Close nipple. 7/. Release brake. 8/. Pump up again and repeat from 3, topping up fluid as needed. Some people swear by these little bleed tubes (Oxford make one called the Little Bleeder, IIRC), which attach to the bleed nipple and are a non-return valve designed to make things easier. It can sometimes take a good few minutes to properly clear out all the air and get decent pressure built up. If, after about 20 minutes, you have no joy, then consider removing the caliper, stripping it down and giving it a good clean out. It's easy when you know how and is detailed in the workshop/service manuals, but we can probably talk you through it. Link to comment Share on other sites More sharing options...
martinshaw94 Posted August 31, 2013 Author Share Posted August 31, 2013 hi just to mention the break systems seals have gone both on the caliper and the master cylinder so the reason for not bleeding properly cheers for all the help as it helped me very much but after nothing happening it came down to stripping the whole lot down to find out the problems cheers martin Link to comment Share on other sites More sharing options...
dt502001 Posted August 31, 2013 Share Posted August 31, 2013 YO martin next time remove the fluid from the lines and master before pushing the pistons back,and clean the piston of dirt and brake dust,then flush the whole system with new fliud. Pushing the old fluid back into the master tends to dammage the seals,the master ,(as task said this stuff collects moisture fast) corrodes and the metal goes down into the lines when you push the fluid back it tends to tear the rubber seals. and the dust seals at the caliper aren't 100% sealed so when you push them back in your pushing dirt into the seals that do all the work. But you kinda know that now Link to comment Share on other sites More sharing options...
Recommended Posts