Difficult without proper diagnostic gear, so that rules out us at home until AndyW's contacts come good. There should be a function on the system to do it - if not then it's a fairly major shortcoming. I've witnessed dealers not inverting the rear caliper to bleed, unsurprisingly a short time passes and the pedal goes mushy again, so it wouldn't surprise me to find that the same happening with the ABS. All things considered, this seems to be the best option especially for the home user.
You'll have to excuse me sounding a bit (or very) thick but I've never bled an ABS system before so how do you go about doing this? I've got the banjo bolts with bleed nipples ordered and plan to fit them next weekend then bleed the system with a vacuum bleeder but had assumed it was just a case of dragging the old fluid through and keeping the reservoir topped up but if I need to do something else as part of the operation I'm better knowing in advance.
AirCon, it will be great if this works, but I'm not holding out much hope for it being the final solution to the 'piss poor' rear brake. My reason for saying this is that a friend has a base model non abs mts, and his brake was appalling too. His has been much better since he did a cat bypass with a new full exhaust system, on the basis that the cat was cooking the fluid. I did wonder about fitting bleed nipples at the abs pump when I swapped my front calipers over, but didn't bother in the end. Anyway, keep us posted, would be great if it is that simple.
If Ducati can design and build the bikes surely thay can come up with procedures to properly maintain them, it isn't rocket science.
Does a vacuum bleed system evacuate the whole system then flood it with brake fluid or just draw fluid through the system using a pump ??
I have to agree with John W mine is a base model (no ABS) and my rear brake is very poor, it won't stop the bike freewheeling down hill. I've bled it with the caliper held high above the master cylinder, got loads of air out, put almost half a litre of fresh fluid through and deglazed the pads all this for almost no improvement yet the pedal feels firm ie no sponginess. My personal belief its just not man enough, looking at other bike systems the caliper piston seems rather small.
No, it just lowers the pressure at he nipple causing fluid / air to be drawn instead of pumping the peddle/lever and having to lock off each time. Can give false air bubbles if the tube to nipple seal is weak. I'm sure someone will make a joke of this.
Ok. If the base model is still piss poor, then I may be wasting my time. To be fair I was actually trying to sort out a spongy feeling in my front brake. Which is now great, like my 998. I'm going to replace the rear disk with a wavy and hh grade pads. After that upgraded master and slave (probably lockheed). I'll keep you all in the loop. New readers please note the mutley is the best bike in the world and I'm trying to make it better.
Aircon, try the HH pads first, they make a sensible improvement, but the pedal still goes away. I was going to fit a wavy disk but having ordered two different types (Galfer and Braketech), both were on a daft delivery time, so I cancelled. I don't think the rear caliper is the problem because its the same as was on my ST4S and that was fine with a decent set of HH pads and 'Braking' wavy disk. So while you might bet a better brake I don't think it will fix the pedal going away. Personally I think the problem is the master cylinder bolted to a lump of frame that gets bloody hot, plus the hoses routed very close to the rear header and cat. I have some heat reflecting tubing to put over the hoses when I get chance this winter. I did start to make a bracket for the master cylinder, but just not got enough time to finish the job yet. Cheers, John.
Does anyone know the diameter of the rear master cylinder? I've been considering the possibility of replacing it with one that has a larger diameter (if possible) which will mean less travel of the pedal for the same amount of fluid shifted. Brembo do that type of M/cylinder in 11mm and 13mm dia. bores.
Is the possible issue with the rear brake caused by its proximity to the hot cat causing the fluid to boil? I would be interested if Decatted bikes suffer with the same problem after repair?
I have a full Termi with no cat and the rear brake is still crap, hot or cold. Bleeding made no difference. It is absolutely impossible to activate the ABS by standing on the pedal. It passed the MoT in May - just!
I've a QD system with no Cat. I blead the rear brake with the calliper off, help up higher than the master cylinder and its been fine for over 12 months or so now.. Decent feel, not the most effective in stopping power I must admit...But activates the ABS if I push it hard enough. But a decent brake for use in traffic and slow riding which is all I use it for anyway!!
im still confused as brake fluid should be the highest grade to stop boiling and also if its a sealed system where is the air getting in, my bikes just done 2000 miles and its been shite since day 1, surely we shouldn't have to muck about with bikes that aren't exactly cheap, I never had trouble with my Rice grinder
Again, in my experience there are not many bikes about with what you could call quality rear brakes. Most are average at best, The main issue is the air getting in the system. where is it coming from? and to keep ocurring something is really wrong. Having said that My rear brake was "dealt with" at the last service and iv'e had no real problems since, it steadies the bike going into corners and holds the bike me the wife and luggage without any issues.
Mines a LeoVince decat, however my brakes were terrible, back now front, after my ride back from CJS. For the purposes of this forum I was riding like I stole it. So may be heat is an issue. Certain old school ducati racers swear by new fluid after every race, may be some truth in the boiling issue.
Satzoomer, the air isn't getting in, it's separating from the fluid at temperature. Think of boiling water, and how you see the bubbles form from the liquid. The same happens with brake fluid, just at a higher temperature. I can't recall what HH stands for, but they are metal sintered pads which give better initial bite. There is a gg apparently too that is meant to give better feel, but never tried them. IMO the standard duc pads are just too hard and lack any feeling or bite. By comparison my r1 rear brake is superb, and mt st4s was great too, so rear brakes can be good. :wink:
