XT M8000 Bleed Issue

ashes_mtb

ashes_mtb

Has preferences
Had to install a new hose for my rear XT brake and am having a hell of a time getting them going. Still getting no lever feel or movement at the piston.

Barb and olive are in good and no leaks.

Ditto at the banjo, remembered the o-rings and there's no leaks there.

Have pushed oil up from bottom to top with a syringe about 6 times. Oil comes up into the funnel with no air bubbles.

Also tried just a gravity bleed from the funnel down. Both with just gravity and also pumping the lever.

No air bubbles coming out in the funnel when I pump the levers with bottom bleed point shut.

Got me beat - any suggestions?
 
S

Scotty675

Cable thief
Have you wound the free stroke screw out and given the lever quick flicks. Seems strange, must be an airlock somewhere.
 
P

peanut

Likes Dirt
There was a video on pink bike recently of jason marsh (gregs mechanic) teaching greg Minaar how to bleed his shimano brakes via video.
As mentioned above opening the free stroke screw & flicking the lever a lot was part of the process in the video. worth a look.
 
Oddjob

Oddjob

Merry fucking Xmas to you assholes
A few things I find important when bleeding Shimano.

1. Closing the bleed nipple and giving the lever quick flicks to dislodge bubbles.

2. Putting a little bit of extra oil in the cup, then pushing the oil up into the cup and then sucking it back out into the syringe. Note keep the syringe upright to let the bubbles rise to the top.

Finally once you've closed it all up it takes a couple of lever pulls for the system to pressurise.

Sent from my SM-G970F using Tapatalk
 
N

northvanguy

Likes Dirt
And I always adjust the lever angle in the bar so that the oil in the cup us almost about to tip out of one edge....then pump the lever, rotate the other way, repeat.

The angle always seems to find some air.
 
ashes_mtb

ashes_mtb

Has preferences
Thanks guys. Last attempt followed this video from the Syndicate guys but still got nothing.

I've got the yellow brake block thing in while I do this - is that right?

 
moorey

moorey

call me Mia
During bled...Lever all the way out, servo wave all way in? (Reset reach, and screw out servo wave after finishing)
After removing funnel and replacing reservoir screw, apply a bit of pressure on syringe at caliper end and close off bleed nipple with pressure still being applied.
 
fatboyonabike

fatboyonabike

Captain oblivious
yes, you need something in your calipers to act as the pads and rotor
have you tried tapping the caliper a few times with something wood to dislodge any bubbles trapped in the caliper, then tap the brakeline every 2 inches to chase the air out, do this all the way to the lever..bleed, check, repeat!
is the bike sitting level or have you got the lever much higher than the caliper, this will help
 
moorey

moorey

call me Mia
fatboyonabike said:
yes, you need something in your calipers to act as the pads and rotor
have you tried tapping the caliper a few times with something wood to dislodge any bubbles trapped in the caliper, then tap the brakeline every 2 inches to chase the air out, do this all the way to the lever..bleed, check, repeat!
is the bike sitting level or have you got the lever much higher than the caliper, this will help
Click to expand...
A master bleeds with caliper in situ so the rotor is the perfect spacer.
And only fucks up 1/3 times and has to clean copious amounts of oil off rotor, caliper and pads.
 
fatboyonabike

fatboyonabike

Captain oblivious
moorey said:
A master bleeds with caliper in situ so the rotor is the perfect spacer.
And only fucks up 1/3 times and has to clean copious amounts of oil off rotor, caliper and pads.
Click to expand...
you can use a pair of "stunt pads" too to make up the gap, an old set that aren't too badly worn but are badly contaminated from poor workshop practices will do perfectly.
 
moorey

moorey

call me Mia
fatboyonabike said:
you can use a pair of "stunt pads" too to make up the gap, an old set that aren't too badly worn but are badly contaminated from poor workshop practices will do perfectly.
Click to expand...
Where’s the thrill in that? The 2/3 times you get it right, you save 10 minutes. The other 1/3 you lose an hour,
Also, badly contaminated stunt was pads will contaminate your rotor. Your method gives the worst of both worlds.
@ashes_mtb, my first post is 100% legit. Will firm up your lever feel assuming everything else you’re doing is correct. Never gravity bleed, imho. Air bubbles rise.
 
fatboyonabike

fatboyonabike

Captain oblivious
I remove my pads and swap out, take caliper off and use a stack of old business cards to act as the rotor, held in with a rubber band..It works for me, but you do what ever works for you...never had an issue.
 
moorey

moorey

call me Mia
fatboyonabike said:
I remove my pads and swap out, take caliper off and use a stack of old business cards to act as the rotor, held in with a rubber band..It works for me, but you do what ever works for you...never had an issue.
Click to expand...
Why not just use a proper pad spacer if leaving pads in? You’re surely 1/2 retarded.
363207
 
moorey

moorey

call me Mia
fatboyonabike said:
because even if you get a small amount of fluid in the caliper, the business card has this amazing property of being adsorbent and soaking up any fluid sitting in and around the pistons, which aides in the cleanup..
Click to expand...
If you get even the slightest amount of oil on the caliper, it’s a thorough clean either way. Also, business cards are super waxy. Use inside out cereal box cardboard, amateur.
 
You must log in or register to reply here.
Top