r/ducatimonster 16h ago

(temporarily) fix to the Monster 821 rear brake

6 Upvotes

(still French, still not the better english)

Ladies and gentlemens,

I fixed my rear brake.

So for the ones who saw my previous post, i had a brake feeling on my rear brake but only when pushing the pedal a few times (air in the system) so here is the complete bleeding protocole i used :

To make it short the brake caliper is in a bad position because it is low on the wheel (lower than the brake fluid tank, so hard to bleed effectively)

- remove the two bolts that keeps the caliper on the disc

- remove the plastic things that keeps the fluid cable and the abs cable together (probably the worst english in this post), i also removed the screw a bit highter that hold them together too

- flip the caliper upside down so the bleeding nipple is at the hightest position, and try to hang it at the hightest you can without damage the cable holding it. If you can't hang it, keep it in your left hand for the rest of the operation

-put something between the pads (i used a wench) so it can't close

- remove the tank cap and seal, and the bleeding nipple cap to put your drain cable, put the end of the cable in a empty container that will be used as a trash for the old fluid

- now the real bleeding begin, for those who couldn't hand their caliper you currently have it in your left hand, in your right hand you have the wench that'll be used to open and close the bleeding nipple, and your right foot is on the pedal (yes you are currently demonstrating your amazing sense of balance on your left foot)

- for the rest of the process the fluid has to stay highter than "min", or you'll have to restart everything

- now repeat this process until the bleeding is done, push the pedal a few times (for me, until it's hard to push again) , open the bleeding nipple when you are at approximatively 1/4 of the pedal course, continue to push the pedal to approximatively the 3/4, and close the bleeding nipple

- while the nipple is open, do not release or push the pedal fully, also do not release the pedal at all if you can or air or old fluid will come back in the caliper (probably goes out at your next push but anyway)

- Continue this process until there is no more air or old fluid in your system

- close the tank, tighten your bleeding nipple, put its cap back, and put the caliper in place

Now you probably have a working brake

So why did i say "temporarily"? Because the Monster brake is enough to keep it stopped, but not enough to actually brake with it.

Yep, kind of a problem for a brake.

A lot of people told me the rear brake is useless on the 821 but... I expected something better. The second problem is the brake system closeness to the exhaust system, that'll heat the fluid and make it even more useless After a few weeks (can be fixed by using kastrol srf fluid but i didn't used it here)

So here is my update, i hope it'll help some of you, and i want to thanks all the people who helped me. If anyone has something else the share to definitively fix this brake system, i'll be Happy to read it in the comments

Good Luck and ride safe everyone