Shimano XT M8000 Brakes - Lever slow to return

Nautonier

Eats Squid
I have some M8000s which haven't seen a lot of use that have developed a 'sticky' RH lever. It doesn't snap back like the other lever and feels awful to ride with. Has anyone else had this issue with M8000s? Quickest, cheapest, easiest solution?

I did find an interesting thread on the issue here:

http://forums.mtbr.com/brake-time/slow-brake-lever-return-m8000-1028345.html

Not sure if I can be bothered taking the entire thing apart though, I got them from Cycling Deal, so might call them and see about a warranty replacement.
 

rone

Eats Squid
Try a quick blast of silicone in the lever mechanism, but it's probably an early M8000 lever and comes with associated warranty issues.
 

Nautonier

Eats Squid
Not something I've encountered with any of the current-generation brakes, and only rarely on the previous generation, a grand total of three times (2x M785 XT, 1x M615 Deore).
Sounds like I was unlucky. What was the fix with the old XTs?

Cycling Deal said they will send them back to Shimano if I return them, but this could take several weeks, so I'm hoping for a faster solution. New levers are $65, which is tempting but seems excessive when they might be fixable. I have read that the M8000 brakes weren't designed to be as serviceable as the older design, I guess the rationale being that the price is so low it's not worth the time to fix them.
 

rone

Eats Squid
Is this a known issue with the early M8000s?

No joy with silicone spray.
Early M8000s suffered from tolerancing issues, unofficially. Get your lbs to send the faulty levers back to Shimano. You'll have relacements in about a week.

Allegedly.
 

The Duckmeister

Has a juicy midrange
Sounds like I was unlucky. What was the fix with the old XTs?
Only one I succeeded in fixing, despite exactly the same procedure for both units... separated the lever from the reservoir/bracket casting in order to pull the master piston out the back of the bore, "polished" the bore with a rag wrapped around a screwdriver, nothing particularly abrasive, and lubed the piston seals with suspension oil (ONLY use this in mineral oil brake systems, not under any circumstances in DOT fluid systems!!!) before reassembing.

Should still be able to disassemble the current series in much the same manner, they're pretty similar, although I haven't closely looked at how readily the lever pivot pin can be extracted.
 

Nautonier

Eats Squid
Only one I succeeded in fixing, despite exactly the same procedure for both units... separated the lever from the reservoir/bracket casting in order to pull the master piston out the back of the bore, "polished" the bore with a rag wrapped around a screwdriver, nothing particularly abrasive, and lubed the piston seals with suspension oil (ONLY use this in mineral oil brake systems, not under any circumstances in DOT fluid systems!!!) before reassembing.

Should still be able to disassemble the current series in much the same manner, they're pretty similar, although I haven't closely looked at how readily the lever pivot pin can be extracted.
Thanks, I might give that a go before sending them back to the shop.
 
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