Whitters Posted May 24, 2017 Posted May 24, 2017 Hi All,So I just got back from Sani where I ended up riding 1/2 of day 2 and day 3 with only a rear brake, not great. So this is what I experienced. I have Shimano XT brakes, recently serviced at cycletech. About 50km into day 1 I realized my front brake was tightening up as I was riding but pushed through to the end. Asked one of the local mechanics to take a look. day 2 the decent was fine but then started tightening again. by the 70km mark there was zero play in the lever and the brake was tight on the caliper. flipped the bike over and manually opened the calipers. I then rode the rest of the way to the sea without the front brake. it worked when I needed it but if I used it I would need to stop within a few minutes to manually open the calipers to release the brake pads. Basically the brake would not release once used and the leaver would take earlier until there was no play when braking. It back in the shop and the feedback I have gotten is it is a problem with the lever and shimano don't carry spares so I need to replace by brakes...? for now I've opted to just have hem cleaned up and see how it goes but with Dusi2C in 3weeks time I don't want to have a repeat of my Sani experience. Any advice?
the nerd Posted May 24, 2017 Posted May 24, 2017 Yep common issue on shimano brakes, the piston gets seized in the lever... Some guys have managed to get it smooth again but not sure whats involved with that...
BaGearA Posted May 24, 2017 Posted May 24, 2017 Take the brake to a trusted mech and have him sand the pistons a bit ?
FCH Posted May 24, 2017 Posted May 24, 2017 I have the exact opposite problem, my back break remains slack, properly bled and topped out- the breaking power is negligible when under weight (ie- off a bike stand) thought it was pads; nope; oil, nope..... not sure what to look at further.
PeterF Posted May 24, 2017 Posted May 24, 2017 https://community.bikehub.co.za/topic/155987-fixworkaround-shimano-xt-m785-brake-lever/page-1?hl=meezo
Mr lee Posted May 24, 2017 Posted May 24, 2017 Which version of XT are you using Whitters? M8000 or M785 or older? How old or how many Km's do you have on the set in question?
Mr lee Posted May 24, 2017 Posted May 24, 2017 Are these brakes the new M8000, or older gen?Beat me to it
Whitters Posted May 24, 2017 Author Posted May 24, 2017 I would guess only about 3000km on the brakes...
ChUkKy Posted May 24, 2017 Posted May 24, 2017 Hi All,So I just got back from Sani where I ended up riding 1/2 of day 2 and day 3 with only a rear brake, not great. So this is what I experienced. I have Shimano XT brakes, recently serviced at cycletech. About 50km into day 1 I realized my front brake was tightening up as I was riding but pushed through to the end. Asked one of the local mechanics to take a look. day 2 the decent was fine but then started tightening again. by the 70km mark there was zero play in the lever and the brake was tight on the caliper. flipped the bike over and manually opened the calipers. I then rode the rest of the way to the sea without the front brake. it worked when I needed it but if I used it I would need to stop within a few minutes to manually open the calipers to release the brake pads. Basically the brake would not release once used and the leaver would take earlier until there was no play when braking. It back in the shop and the feedback I have gotten is it is a problem with the lever and shimano don't carry spares so I need to replace by brakes...? for now I've opted to just have hem cleaned up and see how it goes but with Dusi2C in 3weeks time I don't want to have a repeat of my Sani experience. Any advice? I had the same issue a few years back on my SLX M675 brakes, very sticky lever and essentially left the brakes binding.Ended up cleaning a lot of gunk out by the lever and the piston, looked oily mixed with dust. After the clean, sprayed some Q20 in there and cleaned again and its been perfect ever since. Basically perfect for the last 3 years. Cant tell if it will be a fix for you but I had the exact symptoms you describe.
Meezo Posted May 24, 2017 Posted May 24, 2017 https://community.bikehub.co.za/topic/155987-fixworkaround-shimano-xt-m785-brake-lever/page-1?hl=meezo here's the fix!!! shouldn't take longer than 1-2hours
BLACKvoodoo Posted May 24, 2017 Posted May 24, 2017 I think the strokes too short in your hydraulic cylinder and you're getting premature pressure release.
BLACKvoodoo Posted May 24, 2017 Posted May 24, 2017 It always amuses me when the keyboard tappers on here try to give technical advice. Q; My bikes wheels are flat.. A: Check that your house is north facing and that Orion's belt is just visible. PS. Did you taste it?
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