XT M8000 Bleed Issue

[The Duckmeister]

Maybe you have, but what you think you're adjusting and what you're actually adjusting aren't the same thing.

Yes I'm cranky; life's somewhat not nice at the moment. Pedantic?That shouldn't be any surprise, and.... well... it takes one to know one. (Hell I wish there was a platonic kiss emoti about now.... ;-) )

 

[The Duckmeister]

This little fella. The free stroke screw. Screwed in, lever moves in slightly, but doesn’t bite as quick. Screw out for more bite. Anyone telling you it makes no difference is doing it wrong
View attachment 366071

That lille fella - found only on XTR, XT and Saint levers - advances the master piston down the bore when wound in, thus closing the pad gap to shorten the stroke. It pulls the lever with it, but adjusting the lever is a completely independent action that doesn't change piston stroke.

 

[moorey]

That lille fella - found only on XTR, XT and Saint levers - advances the master piston down the bore when wound in, thus closing the pad gap to shorten the stroke. It pulls the lever with it, but adjusting the lever is a completely independent action that doesn't change piston stroke.

The Q was about XT, so it applies. You may have all the words, I have what bleed process works to give me the best, firmest feel....Something no shop has been able to satisfactorily do on people’s bikes I’m constantly fixing.

 

[gillyske]

Just did an install on some 4 pot slx brakes.
Front brake is firm and strong. Rear not as much. Kept them at their stock lever stroke when doing the fluid top up. Pretty confident i got all the air out, but it is infernal routing.
Am I correct in thinking that adjusting the rear levers stroke to the max and topping up some oil should make it a bit firmer?

 

[The Duckmeister]

SLX don't have stroke adjust. Four-pots can be a bit finnicky to bleed just 'cos of the extra potential to trap air in the caliper. Demount the caliper from the frame and position it so the bleed nipple is the highest corner of the caliper. Plug the bleed cup, and alternate between suction with the syringe to pull air out, and positive pressure to shove oil in. Repeat a few times.

 

[ozzybmx]

Yes thats a good tip, unmount and swing it down vertical and actually roll the caliper around with the bleed nipple pointed up, I've pushed oil through till it was clean, disposed of the dirty stuff, then pushed clean oil through to the cup.
With the cup full and no air in the hoses or lever, start back pulling the syringe and suck clean oil back, you may get some bubbles coming in around the bleed nipple on the caliper, you dont want that shooting into your caliper with the cup closed.
You can back plunge with the cup open, then shut, open, shut to suck the air from the caliper.
Always pressurise the system before closing it up.

Also, if you are pushing clean oil back and forward, just squirt it back into your clean mineral oil bottle, dont waste it. You are only using it to search for bubbles.

Have not owned a set of Shimano 4 pots yet, got plenty of 2 pots. Many sets of 4 pot Hopes, sticky pistons was not a favourite memory.

 

[moorey]

@gillyske don’t forget, the rear will always feel a little squishier, due to long hose....but only a little...even with saint hoses.
I’ve used Zee and Saint, not XT and lower 4 pot, but what duck said.