Fix/Workaround: Shimano XT M785 Brake Lever

[spyghost]

That's the plan. Also I'll be draining all the fluid from the caliper up just to start things clean.

[spyghost]

ok, i've put things back together and rebled....

 

it's snappy again!

 

amazing how a little cleanup has done!

[-cK-]

This needs to be a sticky topic

 

Sprung a leak on my M785's found this topic, stripped down my old M395's that I kept as a back up and boom piston is a perfect match.  Bled the system last night and checked it this morning and no leakage visible so far.  Will refit the brakes tonight and take it for a test spin tomorrow.  So here is to hoping this just saved me from having to fork up a lot of $$$ for new levers/brakeset.

 

Oh and I'll post some pics later tonight but considering the issue described and looking at the original piston of the M795's that is made of some sort of plastic/Teflon compound I much prefer the alu piston of the M395 I scavenged as it feels much smoother and snapper than before.  Oh and for the wight weenies the Weight penalty is negligible imo

 

If this works I might just end switching the other lever's piston as well.

 

[Meezo]

still haven't got around to posting some proper pics, will try and get it soon, got some levers i need to repair!

 

there are quite a few sets of XT/SLX/XTR brakes in the classifieds that can be repaired

[Pusher]

Is there a trick to fit the lever with the spring that goes on the bottom of the lever! Just can't get it to fit with two hands!!

[Meezo]

Is there a trick to fit the lever with the spring that goes on the bottom of the lever! Just can't get it to fit with two hands!!

 

push number 5 in first diagram, slightly through the "body" then the lever then push the spring in afterwards

[spyghost]

Is there a trick to fit the lever with the spring that goes on the bottom of the lever! Just can't get it to fit with two hands!!

Do it while it's clamped to your bars. Inserting the pin just to keep the lever in place will help.

[Meezo]

push number 5 in first diagram, slightly through the "body" then the lever then push the spring in afterwards

 

added to this, it also does help turning the "free stroke" screw all the way in

[mxjunke]

Just found this thread now, I have the same issue with my XT brake. I will try this fix even though I have ordered a new lever already. 

[Pusher]

Thanks guys. Got it in. Phew!

Thanks for the thread, life saver!

[Weimaraner1]

Alls well now. No leaks on the hose, i think it was the lever that was leaking.

 

I was @GECOCYCLES yesturday and had a chat with the tall mechanic, awesome guy for all the help and advice. He says the problem is with the XT caliper. The bleed nipple and hose are both on the same side of the caliper and with the way the caliper mounts the bleed port is always lower than than where possible air could be. When you gravity bleed theres not enough pressure to push this "air pocket" out. You need a big syringe to suck it out of the bleed port.

 

Got myself a 50ml syringe and attached it to the bleed port, filled the funnel with oil and pulled quite hard on the syringe. There was a shiit load of air stil in the system even though i bled it numerous times yesturday.

 

The brake is now solid, full of power. Really glad i went into Geco cycles yesturday. Defnetly my new LBS

 

Thanks for all the advice and the diagram to strip the lever

The mech I think gave good advice. De-gassing the caliper is a method used when bleeding Avid brakes and I also do it now in my m985 xtr brakes and yes it works well.

[spyghost]

what do you think of having a vacuum pump setup similar to tektro?

 

https://www.bikerumor.com/2016/09/03/eb16-trp-brake-checks-aaron-gwin-auto-pumps-bleed-gets-aero/

[BaGearA]

Ok first of all can I do this to previous gen SLX brakes ?

 

Only becaise they feel A little gritty (I suspect they are very very dirty inside) no locking up levers just feel spongy and return A little slow.

 

 

Also I want to fit braided hoses (just for looks) where can I find some good quality ones ? no luck with CRC

[Meezo]

Ok first of all can I do this to previous gen SLX brakes ?

 

Only becaise they feel A little gritty (I suspect they are very very dirty inside) no locking up levers just feel spongy and return A little slow.

 

 

Also I want to fit braided hoses (just for looks) where can I find some good quality ones ? no luck with CRC

 

yes it will work on slx brakes as well.

 

and

 

http://www.wiggle.com/hope-stainless-steel-braided-hose-kit-with-connector/

 

otherwise check bike-discount, bike24 and bikeinn, even merlincycles and evans cycles might be able to help

[BaGearA]

First off I must stress that I am by no means a qualified bicycle mechanic, I do have little very little experience with them. Secondly I cannot take full credit for this fix, the idea was given to me by a very very generous hubber who’d had offered to fix for me for free. KUDOS @BikeWhisperer and a close friend @gyro for the time

Ok, then this is not an avid or shimano appreciation thread, nor an avid vs shimano thread.

 

SYMTOMPS:

Pull lever, and it does not return at all or very slow and spongy.

If bike in open sun, levers lock up.

 

POSSIBLE CAUSES:

Dirt and grime build up in the lever cylinder, as well as on the piston. See below

With the dirt and grime build up, when in heat the swelling cause the lockup and no return of lever.

 

TOOLS NEEDED:

2mm Allen Key

Star Screwdriver

Isopropyl Alcohol

Toilet roll/Roller towel

Thin Nose Pliers

1 x 3000 grit Sand Paper

1 x 2000 grit Sand Paper

1 x 1000 grit Sand Paper

 

This is from the shimano site, I will make reference to the number here in my photos as well

xt_brake_lever copy.jpg

For starters is always good to remove the lever completely off the brake line.

Below is an image of a lever I had repaired and one that was going to get repaired, taken as is off the brake system

20151201_192703.jpg

Remove 8 in diagram above like below, there a tricky little rubber cover than can be removed with a thin small screwdriver or pin

20151201_192730.jpg

20151201_192856.jpg

Push out 5 using the 2 allen key, this will separate the lever trigger from the rest of the lever

20151201_192925.jpg

20151201_193020.jpg

 

How to i get 5 out ???

 

Do i push from the bottom up or the top down either way it won't budge , previous gen SLX 

[Meezo]

How to i get 5 out ???

 

Do i push from the bottom up or the top down either way it won't budge , previous gen SLX 

 

you did remove 8?

 

then bottom up, ie. turn the lever with the name SLX facing down, and pushing 5 out