Non S dude here… ( thankyou Harry B ) So just to be clear, the bike is a 2013/14 twin spark MTS (non S model) with full manually adjustable suspension. Brembo P432 Callipers with 320mm Discs I was going to upload a detailed “how-to” post with lots of images and a list of tools, equipment and lubricants used, but in the end I decided to make this a simpler post of the problem I had and how this work has transformed the brakes on my MTS. Yes it’s technically not a difficult job but even I had some unexpected problems, so please accept this in the spirit in which I am sharing. This is my first Multistrada and in fact my first Ducati, and overall I have been absolutely delighted with my MTS. But two areas have been a disappointment, the first being the seat (which has now been addressed – see separate posting) and the second area has been the brakes. I was really expecting much more from a Brembo equipped bike, especially a Ducati MTS, but from day one of ownership (January 2019) I felt something was missing. Don’t get me wrong the brakes are great and I had no real lack of stopping power, but for me it was a lack of feel at the lever and especially when braking deep into turns … it was missing that fine control and connection to the front tyre / road. The first thing to mention is user error…. That’s me. I knew that the Bosch 9ME ECU had 3 different setting, But did not fully understand the linked setting on ABS 2 which for me at least affects the feel at the brake lever. I know I should have read more thoroughly the user manual, but now I know. I was riding most of the time in Touring mode which has a default ABS setting of level 2, but it turns out this is the “linked brakes” setting and once I changed this to Level 1, things improved as this setting is not linked. So one small improvement achieved. Still not happy, I decided to remove the front callipers (brake fluid had been changed by the dealer at the Desmo Service) and check the pads and test for smooth piston movement. I found that only one piston on each calliper was moving (to my satisfaction) smoothly, so I thoroughly cleaned both callipers and each of the (eight in total) pistons. Once everything was clean and dry I lubricated each piston and then very carefully worked each piston in and out by hand until they moved smoothly and all four pistons in each calliper worked in unison. Now I have to say I am a professional mechanic, 35+ years, but even I had an unexpected problem with one of the pistons “popping out” during the lubricating and freeing off process. I am lucky to have all the necessary tools and equipment to deal with such a problem, but I do feel this is not a DIY job to be tackled at home unless you know exactly what you are doing and have the equipment and experience to deal with the single most important system on your bike. This is why a changed the post from a How-to, to a shorter information post. BUT…. I have to say the difference to my bike after this calliper service is simply amazing. I did not think that the overall braking performance would improve… but it has, and the first real emergency brake test I did after the calliper service was incredible. The big improvement, is now I have the feel and control ( brake modulation) at the brake lever I had hoped for, it’s just so different from before. I can’t describe in words how different the brakes feel. This is how it probably was meant to be when the bike was new in 2013. I hope this information helps, I’ve included just a couple of images, but this is just a few from the many stages that need to be done. Also, did some Carbon wrapping while I had the front fender off…. smile Carl
Thank you for sharing. Yes, I can understand both your impressions of missing the fine control and the fact that it has improved after the deep cleaning. The problem with P4-32 is in the tolerance between the pistons and the seals: Sometimes it results in a mushy brake, sometimes it feels like it wants to brake too soon or too late, and it is because the pistons don't move always in the same way. A clean system is always a good choice, but eventually I changed them with DVT calipers m4.32 (not the mono block ones, the grey ones) and they are much more stable
Great information. What did you use to clean the pistons and calipers ? Also, what was the issue with getting the piston back in ?
Hi John Sorry for the delayed reply, I did see your message in May but was unsure how to answer. The thing is....and I am sure your aware of this, on many forums there are members who really shouldn't give advise on critical systems unless they really know what they are talking about. Ive read some horrific recommendations on materials that should or can be used, and this is why I changed my original plan to post a "How to" with a full list of what I used, for a simpler "information only" sort of write up. Hopefully avoiding unnecessary problems. You see, Brembo will tell you only to use brake fluid, and that is how I was taught many years ago. But knowledge and experience change over time and eventually this was replaced with a product called "Red Rubber Grease" as the standard to be used during caliper rebuilds. Eventually this was replaced by alternate high temp Silicone based products. Most manufactures supply some form of lubricant in the service kit ( Yamaha use a product called Yamlube, which is red ) Lucas Girling have their own version, even Brembo supply a grease in a small tube for some caliper rebuild kits. Whatever you use, you don't need much, as most of it will come off once the brakes get up to normal operating temps, so once the caliper pistons move freely everything needs to be cleaned and any excess removed. So providing you stick with DOT 4 brake fluid the above products will be fine. Just to be 100% clear, for a full rebuild I use RRG ( red rubber grease ) for freeing off pistons that are NOT completely removed from the housing I use a silicone based product. Carl
Thanks Carl. I understand your stance on providing how to vs information. I am not a mechanic but I have rebuilt many cars and bikes, so there isn't much I can't do, unless I don't have the right tools of course. I have rebuilt a bunch of calipers (currently have a pair of Grimeca calipers for my trials bike in bits), and was just interested to hear what you used. As you say times change, and I'm always open to learn of better techniques or products. I use castrol red rubber grease too, and generally try to use Motul RBF600 fluid. I would still be interested to hear what you actually cleaned them with, as it looks like a bucket of soapy water I use water for the outsides, but use Silkolene brake cleaner for the inner faces around the pistons, etc when changing pads. Wondering if there is a better product. As for the calipers themselves, I have fitted Brembo M4 Monobloc calipers (same as fitted to the likes of a 1098S). If you think your brakes are good now, you will be blown away with how good these are. Having recently bought an MTS1200 Enduro, I will be upgrading the brakes on this too. They are fine for solo but just don't give enough bite or feel when two up for my liking. All the best
Hi John LOL...soapy water indeed. For the exterior clean, I generally use a standard alloy wheel cleaner ( Like Wonder-wheels) or similar but nothing to strong. Then indeed soapy water to dilute - remove the alloy cleaner, then compressed air to get everything dry, and finally as you already know, brake cleaner for the final clean both inside and out. Neo also mentioned about changing the calipers, and that is a possibility in the future. Time will tell.... smile. My rear brake is going soft, after only 2000 Km after the service, so I will probably try the Castrol React SRF Racing fluid, as that seems to fix the overheating problem, that all 2010-2014 version have. Had some free time this week so I've removed the exhaust flap and installed a set of home made graphics ( see separate post ) I have to say, I am sooooooo glad I changed to the MTS... its really great fun.
A timely posting! I followed suit and took mine off, cleaned and checked and refitted. I soaked the caliper in a tub with diluted traffic film remover then scrubbed and rinsed. All nice and clean and moving freely with improved braking.
Carl is there supposed to be an o ring behind the pistons? The same happened to me and I put the piston back in place, but I never checked off there was an o ring behind.
If I’m understanding the questions correctly, there are 2 o-rings in each piston chamber, an inner fluid seal ring and an outer dust seal ring. The piston slides in/out within the o-rings. No o-ring, no seal, dust will get in, fluid will leak out. NB in cross section the rings are not circular but trapezoid.
Yes, that’s my understanding of the calipers I have actually seen and stripped. I’ve not seen more than the 2 listed components in each bore. I have seen seals that are tapered and should only be fitted one way around. This type helps to return the piston slightly to reduce the pads dragging on the discs.
Not sure what your after Mike. There are no orings behind the piston, just the fluid & dust seals the piston glides in/out through. Of you had a piston pop out just clean it, grease it (with the correct type of grease), push it back in and bleed the caliper of any air.
