Skylark Posted November 6, 2013 Share I gave up long time ago having calliper pistons that center - ie retract evenly, I just align the calliper by sight with a even gap either side of the rotor between the pads, works perfectly. I have Hope TEch X2 Evo's and I thought the back brakes were a bit weak so gave them a bleed yesterday, as you should I pushed the pistons in completely before bleeding. Bleed worked hundreds, brakes are sharper but I can push the pistons fully in but after pulling the lever they wont retract evenly, its maybe just on or under 1mm difference but its still there - its always been like that(also on the front calliper) but was hoping a bleed may get things back in spec. Is there a trick or fix for this or is it just a minor issue you live with?In the Hope setup videos they seem to think its quite important for the calliper to be centred to maximize braking power. Link to comment Share on other sites More sharing options...
V12man Posted November 6, 2013 Share You should bleed them with the blocks that are specific to those calliper's in and the pistons hard against the blocks, and the blocks centred in the caliper - if they don't retract evenly, then you should first try cleaning the pistons and seals, and if that does not work, replace the seals - and possibly the pistons too as the next step - lubricate the seals and pistons with whatever that brake uses as fluid - mineral oil or brake fluid. Link to comment Share on other sites More sharing options...
droo Posted November 6, 2013 Share ^ What he said Link to comment Share on other sites More sharing options...
Jewbacca Posted November 6, 2013 Share Hahaha..... What they said. I don't think I have ever seen anyone on this website get 2 posts in agreement in a row ever! But seriously, what he said DR ◣◢, M L and Dan Dob 3 Link to comment Share on other sites More sharing options...
Skylark Posted November 6, 2013 Share Brakes are quite new and hundreds apart from this not centring.So are you guys saying your Hopes/whatever brakes you run all centre perfectly? What are those brake blocks supposed to do apart from keeping the pistons in the caliper during a bleed, ie is there a scientific reason apart from that? Technically as long as the hydraulic system is not over filled with fluid the pistons should automatically center after pulling the levers a few times, or definitely after a ride. Or failing that just push them fully back into the caliper and they will find center automatically when the levers are pulled as the excess fluid will get sent back to the master cylinder/lever Edited November 6, 2013 by Skylark Link to comment Share on other sites More sharing options...
madmarc Posted November 6, 2013 Share Easiest way to stop brakes squeaking is to centre them on the mounting brackets that why they have slots in them. After you bleed replace the brake pads loosen the mounting screws and pull the brake lever, while holding it in tighten the screws. You may need to do it a few times before you get rid of the squeak. also check your rotor, sometimes it's slightly out of true and a small section rubs on the pads while the wheel is rotating. If that's the case you will never get rid of the noise...replace the rotor or use a rotor slot tool to try straighten it. Link to comment Share on other sites More sharing options...
V12man Posted November 6, 2013 Share Brakes are quite new and hundreds apart from this not centring.So are you guys saying your Hopes/whatever brakes you run all centre perfectly? What are those brake blocks supposed to do apart from keeping the pistons in the caliper during a bleed, ie is there a scientific reason apart from that? Technically as long as the hydraulic system is not over filled with fluid the pistons should automatically center after pulling the levers a few times, or definitely after a ride. Or failing that just push them fully back into the caliper and they will find center automatically when the levers are pulled as the excess fluid will get sent back to the master cylinder/lever The blocks should come with the brakes - but often don't.... chat to the local Hope importer - Jason at International Trade and see if they can help. If you use the blocks in when bleeding, then you will be able to put new pads in without rebleeding - if you bleed them for example with half worn pads and against a disk, then chances are you will have to take some fluid out when putting in new pads - not a place you want to be in when swapping pads mid ride/race... because for sure the new pads will bind. And the other benefit is that if you do have a fluid spill, it won't go on the disc - although having fluid on the pads is also something best avoided - surgical spirits is your friend to clean it off - pads and caliper. Link to comment Share on other sites More sharing options...
ChUkKy Posted November 6, 2013 Share I gave up long time ago having calliper pistons that center - ie retract evenly, I just align the calliper by sight with a even gap either side of the rotor between the pads, works perfectly. I have Hope TEch X2 Evo's and I thought the back brakes were a bit weak so gave them a bleed yesterday, as you should I pushed the pistons in completely before bleeding. Bleed worked hundreds, brakes are sharper but I can push the pistons fully in but after pulling the lever they wont retract evenly, its maybe just on or under 1mm difference but its still there - its always been like that(also on the front calliper) but was hoping a bleed may get things back in spec. Is there a trick or fix for this or is it just a minor issue you live with?In the Hope setup videos they seem to think its quite important for the calliper to be centred to maximize braking power. Get Shimano Link to comment Share on other sites More sharing options...
madmarc Posted November 6, 2013 Share Get Shimano or Avids...problem solved Lexx 1 Link to comment Share on other sites More sharing options...
LazyTrailRider Posted November 6, 2013 Share or Avids...problem solved Oh please. TopFuel 1 Link to comment Share on other sites More sharing options...
Skylark Posted November 6, 2013 Share The blocks should come with the brakes - but often don't.... chat to the local Hope importer - Jason at International Trade and see if they can help. If you use the blocks in when bleeding, then you will be able to put new pads in without rebleeding - if you bleed them for example with half worn pads and against a disk, then chances are you will have to take some fluid out when putting in new pads - not a place you want to be in when swapping pads mid ride/race... because for sure the new pads will bind. And the other benefit is that if you do have a fluid spill, it won't go on the disc - although having fluid on the pads is also something best avoided - surgical spirits is your friend to clean it off - pads and caliper. Ja I understand that reason but how does having the blocks in when you bleed relate to the pistons centering after the bleed - essentially from what I understand about hydraulic systems is its only to prevent to much fluid being in the brakes and the pistons not being able to fully retract as a result, ie as you mentioned you can't fit brand new pads but I don't see how using the blocks affect the centering of the pistons once the brakes are back in use. Link to comment Share on other sites More sharing options...
gminator Posted November 6, 2013 Share I had this problem the few days ago, tried loosing the bolts then holding the lever down while re-tightening the bolts. Didn't help much, I eventually just sort of lined it up with the eye, the pistons seem to even them selves out after a few tight squeezes. Brake works like a dream now.... Link to comment Share on other sites More sharing options...
V12man Posted November 7, 2013 Share Ja I understand that reason but how does having the blocks in when you bleed relate to the pistons centering after the bleed - essentially from what I understand about hydraulic systems is its only to prevent to much fluid being in the brakes and the pistons not being able to fully retract as a result, ie as you mentioned you can't fit brand new pads but I don't see how using the blocks affect the centering of the pistons once the brakes are back in use. The blocks don't affect the centering of the brakes at all - you should push both the pistons all the way back in the caliper, insert the block, and press the lever - the block SHOULD land up in the centre - if it does not, then you have to strip/clean/replace the seals/pistons until it does center. (assuming there is no manufacturing fault or damage in the caliper/caliper piston bores) If your pistons are retracting unevenly, then usually the slowly retracting piston has a faulty/dirty seal, and sometimes a damaged/scratched piston that makes the seal not work properly. The 2 forces that retract the pistons are from the seals, and piston knock back by the disc - if your disk is buckled, it can have a 1 sided effect - BUT - you first have to make sure the caliper works properly with out the effect of the disc. Link to comment Share on other sites More sharing options...
Skylark Posted November 9, 2013 Share Yay!!!!I finally solved this problem after years of wondering and swearing.Ey no one on thehub knew this, come on guys! You need to equalize the amount of fluid behind each piston... Put a screwdriver as a lever, levered against the edge of the calliper body and behind the pad on the side which you need the piston to come out more. Then using the screwdriver lever the pad out and then pull the lever - that will allow the piston on that side to come out more and will push the piston on the other side in more. You may have to do it a few times on either side before you get them both spot on. WORKS LIKE A CHARM!!! Here's the Hope guy showing how its done: Link to comment Share on other sites More sharing options...
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