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2015 821 rear brakes

20K views 27 replies 17 participants last post by  Buhgaboo 
#1 ·
Anyone having trouble with their rear brakes on the new 821. Mine are hard as a rock but will not stop. Been to first service in Scotsdale Ducati and they said all is well. I can tell you all is not well. I have had 10-11 Ducs from 907, monsters, St2,916,multistradas and they all had good rear brakes. I really just use them in parking lots and coming to a slow stop. You get real scared when you push down and nothing happens. It has ABS and you can get front and rear to modulate but the rear suck in a normal stop.
 
#2 ·
I would bleed them a couple of times and if you still have a problem, take the bike back to the dealer.
Not sure about the Ducati ABS system, but if air is in the ABS pump you would usually get a mushy pedal, but something is wrong.
 
#3 ·
I don't believe there is any air in the rear brakes because the pedal is so hard. I'm going to remove the rear caliper to see if there are any obstructions not allowing the pads to squeeze. This is definitely a safety problem and the dealer says they are like any other ducatis. You all know that you can slow the bike pretty well with the rear brakes. BTW I do use the front brakes very hard.
 
#5 ·
This morning I took off the rear caliper to check its operation. Nothing binding, pistons move in and out. I wonder if it maybe wrong pad material or master is too small to make the correct pressure. Next time we are in Phoenix I want to ride another 821 or a 1200 and check the brakes.
 
#8 ·
It is a design flaw. All the bleeding and messing with it in the world won't fix it.

New pads or a better caliper or master cylinder might fix it, but pretty much everyone including all the reviewers said the rear brake sucks on the new monsters.
 
#9 ·
Design flaw when talking about brakes should warrant a recall ASAP. Have any of the 821 / 1200 taken the pedal / caliper off and see what could be the problem? BMW R1200S had an almost non functioning rear brake and someone took the pedal /caliper off and found that the caliper worked as other Been no calipers so he started looking at the pedal. He replaced the pivot the pedal rotated on with one of a different metal and moved the location of the return spring and problem was solved.
Googl BMW R1200S REAR BRAKE PROBLEM and it should take you to the Pelican Parts R1200S site.
 
#10 ·
I just totaled my 2015 Monster 821 last night after the rear brakes failed on my hard. I've had my Ducati for about a year and I only noticed the rear brakes not biting for the past two weeks since the weather has gotten a bit better here in Jersey. I'm pretty happy to be alive...but WTF...
 
#11 ·
Hi all.. I am also experiencing rear brake set not being performing like how it should be. Braking needed to be forceful. Braking "normally" like how i did on other bike will not slow down the monster 821 at all.

This is a safety concern as I almost had a near collision due to unresponsive rear braking. Do your local dealer help anything?
 
#12 ·
How many miles does the bike have? My 2014 M1200 had a useless rear brake like you describe (firm pedal but barely slows the bike down) for the first 1,000 miles or so then just kept getting better. I have 10.5K now and the rear brake is excellent. I have never had a soft pedal or any other issues as some owners on here have reported. It sucked at first but then came good.
 
#13 ·
I use my rear brake about 1% of the total time I ride. I can't see how a rear brake, or lack there of, could cause someone to "total out" their bike unless they aren't familiar with riding. I'm not trying to beat you down when I say that but if you were about to panic stop using the rear brake you'd have been **** out of luck anyways when the tire locked up and you just went sliding along.

The only thing I use the rear brake for is trailing the rear tire through a wicked twistie, that way I can trail it to control the bike then stomp on the pedal to cause the bike to become more upright at the exit. My 900SS hasn't had a working rear brake in 2 years. I'm not bragging or trying to boast with that comment. It's just that I replaced the pads and bled the unit. The brakes came back to life for about 2 rides then faded out again. I then tore the caliper apart and cleaned it, then I replaced the master cylinder with a new one. Again the brakes were good for about 2 rides and then went completely soft again. Haven't touched them again since.
 
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#14 ·
This is bugging me as well. I've had a bunch of ducatis and this is the only one with a rear brake problem. I've bled the rear twice and the pedal definitely feels hard so it doesn't seem like it's air just doesn't slow the bike down too well. I've read the proper procedure is to take the caliper off and either raise it or rest it on the top side of the rotor and bleed it that way, anyone try this?
 
#15 ·
Radracer6, I've been told the same thing from my mechanic - that is, that the caliper needs to be raised above the brake fluid reservoir when bleeding the brake. Appearantly without doing that an air pocket can remain in the caliper because of how it sits on the swing arm in relation to how to fluid flows through the caliper during the bleed (I'm not doing a good job of explaining it).

At any rate, when I do that (and when I let the mechanic do it too) the rear brake feels a bit better, but it still sucks. I also have a Ducati Scrambler Italia Independant and the rear brake on that bike is super.

My dealer seems to think this is just a part of owning an 821 (he says the same issue is not appearant on the 1200 because the caliper is held differently on the swing arm), and says everyone who owns one comes in to have it bled once or twice a season. That seems kinda goofy to me.

So, my question is this: If there seems to be no great way to get the rear brake on the 821 to work well can anyone here suggest whether or not a new, different brake caliper might work, and what specific caliper they'd then recommend?

I know the rear brake isn't as 'important' as the front one, and I don't use it much, but the thing is when I do want to use it I REALLY want to use it (think gravel corner and I can feel the front starting to slip out when I apply the front brake), and regardless, the bike has two brakes; they should really both work.
 
#19 ·
I've had a 2015 821 stripe for about month now, I have put about a 1000 miles on it with the stock pads, never been bleed etc. Total mileage is 3300. While the rear brake is somewhat wimpy its is far from non functional. I personally think it's intentional for the type of bike, being a short wheel base naked bike where due the height and weight shift, especially in a hard stop the rear is simple not going to contribute much to overall braking at all with the real good front brakes. I find it fine for trail braking, added control during hard stops, and for low speed u-turns, low traction situations and such and having a real strong touchy rear brake for the most part on a bike like this is a detriment. It's certainly strong enough to skid the rear tire and kick in the ABS if you give a little effort on the brake pedal and it's just not touchy. On another one of my bikes, a 2015 Victory Cross Country, being of long wheel base and 800 lbs, the rear brake contributes a lot lot more to the overall braking of the bike.
 
#21 ·
Rear Brake

I bled the snot out of mine to get it to work but never was able to get a firm pedal feel...I adjusted the push-rod as instructed by manual but that left me hitting the exhaust before fully compressing the caliper...I have turned the push-rod a full turn after taking up the slack and that helped but haven't gone any farther...I read somewhere that if the push-rod goes in to far it blocks the return passage and fluid gets trapped in the caliper which creates drag, heat, eventually locking onto the rotor until something expensive happens...i do plan on giving it another turn but i only need it on steep hills and have been occupied with other issues...but that's for another post...
 
#22 ·
Never adjust the rear master pushrod so that there is no clearance between the pushrod tip and master piston cup.!!
The proper adjustment is to adjust the pushrod to a point where the tip is in contact with the cup then back out 1/2 turn.
If there is even the slightest amount of pressure against the cup - this would result in a locked up rear brake due to fluid expansion from heat in the system as it builds up - due to the return orifice in the master being closed off.
 
#23 ·
I am a full turn past the point it says not to go for sure...but I wonder if that applies to all brembo master cylinders? I've pumped the entire pint of fluid through it in one go so I felt fairly confident it would have solved it...it doesn't feel like air is in the line because pumping the pedal doesn't make much difference...and aside from stops on hills it doesn't get used...I suppose I should give it another look...it worked up until its first oil change and then I just started using the fronts...engine braking alone worked as good as the back brake seemed to anyway.
 
#24 ·
This applies to most any master cylinder - the master piston must always be able to return to but up against the internal snap ring when no pressure is applied.
If you were to have air in the system it is simple to test - you can go by feel at the pedal travel - from the resting point - depress the pedal until you can not push any further with your hand.
There should not be more than an inch of travel at the pedal (approximate ) Do not forget - air is compressable but fluid is not
 
#25 ·
I have a 2017 821 Monster. My rear brake is working, but if the bike stands for a few days I can press the pedal down and nothing happens. Only pushing the pedal down for 6-10 times builds up pressure in the rear brake. Ducati changed the break-pump and now the rear brake saddle, too. I will see in springtime if its working now properly.
 
#26 ·
All the comments have pretty well covered it. I have had many bikes and the rear on my Monster 1200 is the most ineffective I have seen even with proper bleeding and a hard pedal. I installed hh pads with little effect. I shifted the pedal ratio and got some improvement. It is correct that you do most of the stopping on a sport bike with the front brake but it is nice to have a decent rear to aid turn in and help in normal stopping. I suspect the stainless used has a very low coef but can not verify if this is the case. This is my first Duc. I like the bike but quite a few items could use refinement. Clutch lever effort, stalling, poor daylight visability on the dash to name a few. Some have been fixed on the newer bikes and with aftermarket parts. Have fun-T1
 
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