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Rebuild Shimano XT M8000 Lever/Master Cylinder (1 Viewer)
- Thread starter jembourbe
- Start date
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- Thread starter
- #2
Remove the brake hose (the mt8000 uses a 8mm nut hidden under a rubber cover where the hose inserts into the caliper)
Remove the caliper from the handlebar and get as much oil out as you can.
Remove the caliper from the handlebar and get as much oil out as you can.
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- Thread starter
- #3
Then loosen the set screw located behind the plug. Then you can push out the pin.
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- Thread starter
- #4
Now remove the pushrod.
In that photo ^^ it's already twisted out.
(It looks like a dong)
In that photo ^^ it's already twisted out.
(It looks like a dong)
- Thread starter
- #5
Now to get the cylinder and spring out...
There's a hinged keeper holding them in. The hinge pin (it's part of the keeper--all one piece) is at the top, and the plastic plate at the top is holding the hinge in place.
Depress the piston and gently pry out the top plastic plate. Gently! If you break it then you're buying a new lever. Actually that goes for everything you're touching in this job. lol
There's a hinged keeper holding them in. The hinge pin (it's part of the keeper--all one piece) is at the top, and the plastic plate at the top is holding the hinge in place.
Depress the piston and gently pry out the top plastic plate. Gently! If you break it then you're buying a new lever. Actually that goes for everything you're touching in this job. lol
- Thread starter
- #6
Clean everything to operating room perfection
- Thread starter
- #7
Reassemble. If you bought new seals, put them on your piston. Dunk the spring and seals in mineral oil.
- Thread starter
- #8
Put spring and piston in cylinder bore.
Now you're going to have to fiddle the top plate and hinged keeper into place. Be patient. It's easiest (but still not easy) to put them in together, in the correct anatomical position
Once you've done that, snap the bottom plate back in place (if you removed and cleaned it, like you should have).
Next, twist that push rod back into place. You'll need to compress the piston/spring to get it done. It's pretty fiddly too. Be patient. Maybe use your dad's dental tools.
Now you're going to have to fiddle the top plate and hinged keeper into place. Be patient. It's easiest (but still not easy) to put them in together, in the correct anatomical position
Once you've done that, snap the bottom plate back in place (if you removed and cleaned it, like you should have).
Next, twist that push rod back into place. You'll need to compress the piston/spring to get it done. It's pretty fiddly too. Be patient. Maybe use your dad's dental tools.
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- Thread starter
- #9
Now time to reinstall the lever to the body. The big pin should, from top to bottom, go thru:
1. Top of body
2. Top of lever
3. Hole in lever pivot
4. Lever spring
5. Bottom of lever
6. Bottom of body.
The problem here is that you have to line everything up, including the lever spring that you were supposed to note the location and orientation of before disassembly.
I line it all up and hold it In place with a small screwdriver or hex wrench, which I then push out as I replace it by inserting the lever pin.
It's fiddly. Be patient. You'll hate that ****ing lever spring.
That pic kinda sucks. I mean, it's a great pic, but the screwdriver is pointed the wrong way. Don't do like the picture: insert screwdriver from bottom to top, and push it out with the pin going top to bottom.
Last, DON'T FORGET TO TIGHTEN THE PIN RETAINER and put the little rubber plug back in place.
1. Top of body
2. Top of lever
3. Hole in lever pivot
4. Lever spring
5. Bottom of lever
6. Bottom of body.
The problem here is that you have to line everything up, including the lever spring that you were supposed to note the location and orientation of before disassembly.
I line it all up and hold it In place with a small screwdriver or hex wrench, which I then push out as I replace it by inserting the lever pin.
It's fiddly. Be patient. You'll hate that ****ing lever spring.
That pic kinda sucks. I mean, it's a great pic, but the screwdriver is pointed the wrong way. Don't do like the picture: insert screwdriver from bottom to top, and push it out with the pin going top to bottom.
Last, DON'T FORGET TO TIGHTEN THE PIN RETAINER and put the little rubber plug back in place.
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- Thread starter
- #10
Cylinder scoring? What cylinder scoring?
Cross fingers your cylinder doesn't look like this:
If it does, well, you're still probably going to get another year or two out of a bad ass lever. If it looks better than that, then you've got a brand new lever.
Shred on, my shredders!
- Thread starter
- #12
They're all coming from China. <---Linky
How are the seals holding up after 4 years? I just took apart, cleaned, and reassembled the same lever on a new-to-me used bike. All parts looked great so I am hoping transient debris caused the leak. Next step would be these aftermarket seals.
- Thread starter
- #14
I'm still using that master cylinder regularly. It's going to slow me down in Crested Butte next week