[ducatiforever]

Hi, my rear brakes seem to be only just working they will just slow you down they will not lock up and at best rear brake only you can just notice them slowing you down form around 60 km or about 35 miles an hour, even at 20 km or about 12 miles an hour you can still only just notice them.

I have had at the shop twice, the first time they said they were glazed over and to replace them or take the pads out and lightly sand them then replace. So i sanded them and replaced them still no difference so i replaced the pads after bedding them in still no difference so when i went to the shop again i let told them what i had done and they siad it might be a leaky master cylinder and would have a look, when i picked up my bike they said that the rear brakes are fine. I also have a 1098 and they said that they would not be as good as the 1098 but that they were fine, they still don't lock if you stand on them and they still do not have any effect on slowing you down from a slow speed can anybody help me or has anyone else had this problem ant help would be great thanks.

 

[Spudd]

well, I would say your rear brake is fine. The rear brake is small, very small compared to your front brakes, right?. Take that fact to heart and understand that the rear brake is really only for coming to a slow stop, it isnt intended to stop you from speed, that is what those front brakes are for; take it easy on the rear brake....just sayin

 

[Duc_L_over_V]

Did you try adjusting the linkage? How about doing a bleed and fluid replacement?

And for the record, the rear brake is used for steering into a fast turn, although if you don't know what you're doing you shouldn't attempt it.

 

[ducatiforever]

The brakes have been refilled and bleed i am going to try adjusting them and see what happens i understand that the rear brakes are not going to be great but i expect them to at least slow you down from a slow speed.

Should they lock if you stand on them?
Thanks for your help.

 

[Duc_L_over_V]

Yeah, you should be able to lock it up if you really want to. I don't recommend making a habit of it though. I did it once just to test it after I adjusted the linkage and it was... interesting. I wasn't going fast, luckily.:laughing:

 

[ducatiforever]

Thanks for the tips i shall try adjusting and see how that goes but there must be something not working right as at the moment there is no way they will lock.

 

[Slower than you]

The brakes have been refilled and bleed i am going to try adjusting them and see what happens i understand that the rear brakes are not going to be great but i expect them to at least slow you down from a slow speed.

Should they lock if you stand on them?
Thanks for your help.

There is nothing to adjust.

Here's a problem that you can create if you're not careful....
You'll detect the free play in the pedal and like most people, will want to adjust it out. Don't adjust the rod that pushes on the piston very much as the master cylinder needs to retract fully to release pressure when in the relaxed position.

** If the push rod is holding the master in a slightly actuated position, system pressure will build from brake heating and burn the shit out of the pads and rotor. Many people have done thi$$.

Reality:
No the rear brake is not effective.
No you can't lock the tire with the rear brake
Different pads won't improve it
It's used for trail braking and that's all it's good for.

It does work fine for holding the bike still when stopped on a grade though.

Not being a dick, but learn to ride harder and use the front brake only. Then you'll understand why Ducati designed the rear for it's marginal energy input to braking.

 

[Neo-996]

I replced the master cylinder and the pads and the fluid and still haven't locked up the rear. Don't think its meant to lock up, no need to.

 

[ducatiforever]

Thanks for all your help so far but my question wasn't how to use the rear brake, i know that the rear brake is mainly used for trail-braking and when using the rear brake that you use very a small amout about 20%.

But the question was why the rear brake is not working as it should, why when even at a roll say 5km/h clutch in and maxime rear brake only that it takes along time to come to a stop, why the harder i push on the lever the pressure on the disc from the pads does not become greater. My thinking is that i should be able to do this and slowly depress on the lever and i should come to a quick stop and if i depress hard and quick enough it should lock, this is what brakes are suppose to do. Why is it that when i depress the lever that i only get a limited amount of pessure on the disc from the pads and it doesn't become greater.

I am going to bleed the brake myself as last service all fluids were replaced by the shop, {i had the problem before the sevice} if this doesn't work i am going to pull the system apart and see if there is a problem else where, once again that for the help and i shall let you all know if i find a fix to this problem.

If anyone has a fix for this problem i am all ears.

 

[Beer Baron]

I believe you that it's not working properly. when I went looking for my second 996 I rode somewhere between 15 and 20 of them. my first 996 had a very strong rear brake. could easily slow the bike at slower speed (60km/h or less) and easily held the bike on any kind of incline.

about half the 996s I test rode had rear brakes that where no where near as effective. and one or two were completely hopeless to the point on a really steep hill even standing on the thing hard would not completely hold the bike without a bit of front brake help.

your 998 rear should really feel just as good as your 1098 rear. there is not much between them in hardware. so something must be wrong.

there are only a few components to the system that can cause problems.

brake lines - if old they can sometimes expand under pressure giving less effective braking - simply replace with a new braided line if needed.
fluid - old fluid absorbs water and makes pedal spongy, simply replace and bleed fluid.
air in fluid - this also causes spongy pedal and reduces effectiveness - simply bleed the fluid (at the master and the caliper, need to take caliper off to do it).
glazed pads - need to be roughed up or replaced
worn pads - replace
glazed rotor - needs to be honed or replace
sticky caliper - needs a seal kit/rebuild kit
check linkage and the mechanical bits but they rarely give trouble. as one poster said don't take out all the free play as the master has to return all the way or it blocks the bypass port.

simple process of going through all the components should sort it out.

 

[Beer Baron]

as for locking the rear brake. that's pretty subjective.

different tyres will affect it's ability to lock. obviously super sticky/grippy tyres will be hard to lock, cheap hard tyres easy to lock up. road surface has the same effect, high grip surface will make it harder to lock, low grip surface makes it easier. so it's hard to say if in any one case it should lock or not.

 

[pat1098]

There is a trick to bleeding these rear brakes effectively.

If the pedal goes down more than half an inch, with good pads, you should be able to improve it with bleeding.

The 'trick' is to mount your caliper up high on the bike, with a 5mm plate between the pads, clamped to the bike up around where the seat sits onto the subframe.

You need the bleed caliper to be the highest point in the system, with the hose going consistently uphill, so no air can get trapped in dips in the hose.

Syringe out the fluid reservoir and refill with a Dot 4 fluid, and bleed the system until clean fluid matching what you have put in emerges from the bleed nipple. This may take 2-3 reservoirs full to achieve.

If any bubbles have emerged into the clear tubing you are bleeding into you should be rewarded with a better braking response.

 

[Slower than you]

+1 Pat.
If the pedal is hard there is no air in the system. But to bleed it, take the caliper off and hold it upside down.

 

[Beer Baron]

yeah pat has the right idea. when it's mounted like that too give it a few taps with a rubber mallet or something as sometime a little stubborn fucking bubble will be stuck somewhere and a little tap will jostle it loose.

 

[pat1098]

Yep - a tap can help.

I use the plastic handle of a large screwdriver end-on so it gives it a good shock without marking anything. I give the hose a few taps too.

A lot of rear brake systems are 'recalcitrant' to bleed the air out of, because of their layout.

It's just a general approach, where you imagine that if you were an air bubble, where might you be caught in the system?

Makes it pretty simple.

 

[ducatiforever]

Thanks to both Beer Baron and Pat for your excellent info and help with this problem all of what you say makes a lot of sence and should be of great help to me, i shall be hopefully fixing my problem in a couple of days when i get a bit of time. I shall let you all know how i get on with this and thanks again for all your help.