XT 785 brake bleed

[clyde the point]

New lever assembly new banjo hose. Have new caliper in hand. Lever will pump up properly but hold pressure for a moment then lever squishes to handle. Have tried all the tricks I know. What am I missing? Have pushed new fluid up from caliper and bled at lever multiple times. Even put on a new Saint lever attempting to correct. Thanks in advance.

[.RJ]

snug up the compression fitting, and try bleeding it like a motorcycle.

[clyde the point]

Explain MC bleed pls.

[.RJ]

put fluid in the cup attached to the reservoir and put a hose to a catch can on the caliper. Pump up the lever and hold pressure, open bleeder at caliper, before lever bottoms out close it again. Repeat until you dont see any air bubbles.

[calebrichardson]

Not sure if "holding new caliper in hand" means you already tried something like the following, but just in case.

I've found that 785s can be very stubborn about holding an air pocket in the caliper. Depending on the orientation, you can pump all the fluid you want in, but the pocket will stay. When doing a full bleed, I detach the caliper from the frame and let it hang down so that it is oriented similarly to the front caliper, and also make sure that the hose runs upwards only, and has no flat or downward sections.

[clyde the point]

super thanks I will try both suggestions today. new caliper in hand means I bought an extra one cause I think mine might be bad.

[markie]

Originally Posted by calebrichardson

Not sure if "holding new caliper in hand" means you already tried something like the following, but just in case.

I've found that 785s can be very stubborn about holding an air pocket in the caliper. Depending on the orientation, you can pump all the fluid you want in, but the pocket will stay. When doing a full bleed, I detach the caliper from the frame and let it hang down so that it is oriented similarly to the front caliper, and also make sure that the hose runs upwards only, and has no flat or downward sections.

I had the same problem and this worked for me. Gravity helps get the air out of the calipers. It took getting mad and just leaving it over night for it to just resolve itself.

[NHAero]

I have a couple of bikes with those style calipers and agree that detaching and setting them vertically is important to bleeding.

[.RJ]

maybe use some sort of vibration to work out the air bubble?

[dolface]

Originally Posted by .RJ

maybe use some sort of vibration to work out the air bubble?

Tapping the hose w/ a wrench/hex key/whatever has worked for me.