[Freeridin']

I have an XT brake that is being bled for the first time since the factory. I've bled the newest generation of Shimano brakes numerous times...that being said, I cannot push oil through the system.

Pushing oil up from the caliper does nothing. I can apply force to the syringe until the hose pops off the fitting (yes, the bleed nipple is wide open). Pushing oil down from the lever with a syringe results is oil spewing out from the reservoir under the silver XT cover. "Pumping" oil downwards with the lever pushes oil out the bleed nipple but ALL of it is sucked back in when the lever is released.

I've had this happen once or twice before but eventually worked its self out. My last effort was to pump the pistons together and then reset them, I did this multiple times to no avail.

Any ideas?

 

[Kanye West]

Reservoir is blocked at the MC port most likely, or the MC piston isn't retracting far enough.

To test this, try to displace fluid back and forth with the syringe and the lever (hooking the syringe up to the bleeder on the caliper). If you can feel those moving back and forth with one another with ease, your line and caliper and MC are clear.

Then try the same thing with the syringe and the lever, with the syringe hooked up to the reservoir cover. I'm betting you will not see them moving freely back and forth here, which is why you're purging past the reservoir seal.

The fact that ALL the fluid is retracted back in from the caliper bleeder if you cycle the lever also tells me that the reservoir port isn't clear somehow, otherwise you'd get a little bit of refill when the lever came back, and there'd be a tiny bit of fluid left outside the system.

Drain the system entirely and clean out the reservoir and MC body with some IPA (not acetone), or whatever the manual recommends, and do a visual check to see if the port is getting clear when the lever moves. Make sure all the adjustments are backed out.

 

[Freeridin']

The master cylinder port was indeed blocked....I was preparing to drain the system until I read, "Make sure all the adjustments are backed out." Presto!!!!

The freestroke adjustment does in fact do something!! In my case, it was blocking the MC port.

 

[Wolf Hugo]

I have 2010 shimano xt brakes that I'm replacing the levers with 2012 xt ones. I was planning to use a syringe with the plunger removed instead of the "oil funnel" shimano wants me to buy.

 

[Lelandjt]

Should work fine as long as yo can thread it in. Maybe the threads are the same as Avid and Formula bleed ports so the nipple from an Avid bleed kit will allow the syringe to thread into the port.

 

[Dogboy]

I have 2010 shimano xt brakes that I'm replacing the levers with 2012 xt ones. I was planning to use a syringe with the plunger removed instead of the "oil funnel" shimano wants me to buy.

I would personally use the funnel. Being able to tilt the lever forward and backward during the bleed allows the air trapped to easily rise up through the funnel.