Both masters on my MTS are needing repaired or replaced.
OPP Racing informed me that Brembo no longer makes rebuild kits for OE masters and they no longer have any. Gotham has the seal rebuild kits for $50 per side. A different vendor (kurveygurl) said seal repairs must be done by a Brembo service center. RCS replacement units would be a little under $600.
Has anyone attempted the seal repair process? Is it tricky enough to require service center expertise or special tools? It's obviously not a part you would want to fail.
Any thoughts appreciated.
Are they leaking or ?
Quote from: Speeddog on September 04, 2019, 11:49:44 AM
Are they leaking or ?
Clutch requires bleeding every 200-300 miles. After that, friction zone begins to disappear. Bleed and it's perfect again for another 200-300. I replaced the slave with an Oberon unit thinking that was the culprit, but still the same.
Front brake is similar, though I tie it back for 24-hours and it's great for a while until lever travel begins to increase and brakes get a bit mushy. Rinse and repeat.
Thought it might be a pinhole in the line or something, but since its affecting both brake and clutch, I'm leaning toward MCs. Bike has 38k miles on the clock, and these MCs were rumored to be not super.
Down here I take m/c and caliper rebuilds to specialty auto brake shops insured for that work. Sometimes the margin on a rebuild is so small replacement is a better option as long as you dont get too fancy. I may provide the shop the rebuild kits, but sometimes they find matching generic seals (depending on the bike).
Specialty small bore honing tools are expensive here but I dont know your prices up there.
Maybe the next level down in radial m/c's from oem monsters or superbikes will give the feel you need at a better price rather than the top of the range stuff?
I've seen Brembos where the rubber grommet around the plastic elbow fitting will crack and allow the MC to pull air.
They won't leak fluid from that crack, as one might expect.....
Radial masters won't self-purge air at all, as the reservoir feed comes in the side.
So the master itself needs to be bled from it's bleeder fitting as well.
Thanks, guys. I'll take a closer look and see if I can find any cracks anywhere.
The clutch (PR16) I've been bleeding at the master with good results. The front brake (PR18/19) I've also bled at the master with good results. The times it's gone a liitle bit soft, seems like tying the lever back overnight has firmed it up and works for a time. It's definitely not as bad as the clutch.
@koko64 I assumed replacing the cylinder seal would suffice, but if honing is required, I'd definitely have to find a shop. Though I don't know of any that do that kind of work. At $100 in repair kit + labor, I might be better off just replacing them with new.
Thank again.
Quote from: Speeddog on September 04, 2019, 03:36:59 PM
I've seen Brembos where the rubber grommet around the plastic elbow fitting will crack and allow the MC to pull air.
They won't leak fluid from that crack, as one might expect.....
Fittings and tubing all seem to be good --no cracks visible, nor fluid. The dust boot on the clutch has a few small tears, which makes me wonder if some dirt has been introduced and is causing the issue with the clutch. Not sure if that part can be found, either.
Don't really know what direction to go with this...
Yes, you do [thumbsup] There are ENORMOUSLY important reasons to have a trustworthy and confidence inspiring brake master. You won't get there on your own (?) Try to fix the clutch master if you really want, but not the brake side.
Back to OPP [Dolph]
Quote from: stopintime on September 08, 2019, 03:57:30 PM
Yes, you do [thumbsup] There are ENORMOUSLY important reasons to have a trustworthy and confidence inspiring brake master. You won't get there on your own (?) Try to fix the clutch master if you really want, but not the brake side.
Back to OPP [Dolph]
Pretty frustrating; after reading and watching, the procedure is pretty simple and the issue could potentially be fixed with a few inexpensive rubber seals. That apparently aren't available.
Of course, there's still a chance it could be something other than the master [bang]
.... such as the ABS unit? :-\
Quote from: stopintime on September 09, 2019, 01:43:03 AM
.... such as the ABS unit? :-\
Specific to the clutch, I suppose there's a chance of a leak in the line somewhere. The stock line doesn't appear to be braided stainless like the brakes, apparently just rubber. I haven't found any pre-made, so would have to measure and custom order. New crush washers probably wouldn't hurt, either.
ABS was implicated in the issues with the rear brake that plague these bikes. Mine has been good after a good bleed/abs cycle/bleed process, though. Front brakes honestly aren't bad, but the clutch is a PITA when it starts to go, creating challenges at stop/start intersections.
Sometimes a hairline crack occurs on the slave cylinder bleed nipple. Some models had quite a small diameter threaded section prone to cracking under the stress of repeated bleeding.
For the brakes there are probably stubborn bubbles lodged in the ABS unit and you need to put a banjo bleeder there at some stage. You could search for other bleeding methods like syringe and vacuum methods or the sonic method that might dislodge bubbles in various nooks and crannies. I use retired hair clippers with the blades removed which are taped to the brake line. It works like a parts cleaner vibrating the bubbles into the fluid stream while you bleed them. Stubborn jobs have required me to use the regular method and both syringe and the sonic methods to remove trapped air. The final factor is patience as it is tedious to say the least, pita is more like it. You're probably sick of it already from the effort and it shows some of the engineering downfalls of modern ABS systems without enough thought to maintenance. I once fixed someone's brakes that others failed to by bleeding them with alternate methods over two solid hours. The brakes felt and worked great after the sustained effort. I'm sure you've racked up some hours already.
How's it going?
Quote from: koko64 on September 13, 2019, 11:22:04 AM
How's it going?
Well... when my ST2 started giving me fits, I solved the problem by getting the MTS. Now the MTS is giving me fits, I've alternated between working on it and my ST2. And I believe new fuel pump relays for the ST2 have solved that problem.
So if I hold true to form, I may let the MTS sit for a year, pretend I'm shocked that the battery died in that amount of time, and postpone buying a new one because I'm a cheap-a$$ (or more accurately, a dumb-a$$).
Long story, short; I plan to button the ST2 back up tomorrow and either ride it or bleed the MTS again and ride it.
I'll probably go the RCS route with the levers. The clutch has to be leaking somewhere and I still feel both masters are suspect. Time and money will tell!
Just to update... I got a set of RCS levers; 16 for the clutch and 19 for the front brake. Sweet hardware, but ran into some fitment issues. These MCs are straight, so don't have the same angle as OE. While the brake has mounts for microswitch, the clutch lever does not. Meaning I would need a banjo bolt with a pressure switch, or deal with no microswitch, which I'm disinclined to do. Also, the OE's have a bolt hole in the top for securing hand-guards. The RC's lack this, so hand-guards can't be secured there.
Still trying to decide if the combined minor issues = deal breaker.
Since I had the clutch MC off, I decided to take it apart to see what I could see. It's literally a pin, spring, piston, and a snap ring to keep it all in place, covered with a dust seal. Can Brembo really not make a rebuild kit available!?
Regardless, the piston seemed pretty dirty (as in black particles). The dust seal had a few small tears, so it could be ingress but wondering if it's seal breakdown.
Is there a recommended cleaner for piston and seals that won't cause the seals to degrade? Rubbing alcohol?
I'm pretty sure a banjo bolt pressure switch would trigger at too high a pressure to work for the clutch.
No they're fine.
The seal on the piston is the one that really matters.
WD40 is a good cleaner that won't hurt things.
Quote from: Speeddog on September 23, 2019, 09:49:14 PM
I'm pretty sure a banjo bolt pressure switch would trigger at too high a pressure to work for the clutch.
The seal on the piston is the one that really matters.
WD40 is a good cleaner that won't hurt things.
Thanks for that info.
Speculation as to where the grunge might come from. Some feel the line from MC to reservoir is suspect. I ordered up some clear Tygon 2375 to see if that helps at all. Potentially seal degradation, but I can't tell on inspection. Could still be ingress from small tears in the dust cap.
I also learned that there was a recent recall for the 16 brake cylinder for various models. Because of that, the piston kit is available (part #61041881A). I've ordered one to see if it is identical to the clutch and possibly use that, or just the seals if they're identical. Could be that a thorough cleaning of the existing cylinder and seals will do the trick. Hard to say since I have no idea what the source of the leak is.
I'm pretty sure that the contamination in the fluid on the clutch systems is metal from the master and slave cylinder pistons and bores.
IME, it's particulate, if you let it sit for a while it will settle to the bottom of the reservoir.
I don't think it's the black OEM reservoir hose material.
Systems with clear hose or no hose still get black.
Brake masters and calipers move very little in comparison, and my SWAG is that the clutch is actuated 5x as often.
Also, the clutch slave cylinder spends a lot of time quite hot, that doesn't help the fluid at all.
Quote from: Speeddog on September 28, 2019, 09:54:11 AM
I'm pretty sure that the contamination in the fluid on the clutch systems is metal from the master and slave cylinder pistons and bores.
IME, it's particulate, if you let it sit for a while it will settle to the bottom of the reservoir.
I don't think it's the black OEM reservoir hose material.
Systems with clear hose or no hose still get black.
Brake masters and calipers move very little in comparison, and my SWAG is that the clutch is actuated 5x as often.
Also, the clutch slave cylinder spends a lot of time quite hot, that doesn't help the fluid at all.
I'm pretty curious. Looking at the design with it disassembled it seems the only thing that comes into contact between the piston and the cylinder are the seals. It doesn't seem that the seals are stout enough to remove metal from the cylinder?
The piston seems metallic, though not magnetic, so not sure what it's made of. The recalled pistons affected various '15-'18 models and were made of polyphenilene sulphide (PPS). The replacement units are machined from aluminum bar. For whatever that's worth...
When I got the bike, I could see particulate on the bottom of the reservoir. Not a huge amount but enough to notice. I cleaned it out completely. I haven't seen it return, but I've been flushing/bleeding a lot with the leak plus the Oberon slave replacement. When I disassembled the MC, the piston wasn't visibly dirty, but the rag I wiped it with showed quite a bit of the same black particulate. No clue if it's significant enough to compromise operation. Seals appear to be fine to my untrained eye.
Waiting on the repair kit at this point. Funny thing is, Ducati wants $27 for just the MC dust cap. The kit that costs $20 includes it. And I read that the exact same dust cap can be purchased from the KTM dealer for $5. :-\
I believe the black is from heat.
Anybody got access to a mass-spectrometer or some similar apparatus?
What about those oil analysis people?
What do they use?
Quote from: Speeddog on September 29, 2019, 10:09:28 PM
Anybody got access to a mass-spectrometer or some similar apparatus?
What about those oil analysis people?
What do they use?
I suppose you could call one of the oil analyses companies and ask about testing brake fluid for contamination other than water. Or maybe a small local chem lab. Something definitive would be nice. This black brake fluid discussion a has been going on forever. What makes me think heat is the water cooled Multistradas. If the cat is in place, black rear brake fluid.
Quote from: howie on September 30, 2019, 04:45:14 AM
I suppose you could call one of the oil analyses companies and ask about testing brake fluid for contamination other than water. Or maybe a small local chem lab. Something definitive would be nice. This black brake fluid discussion a has been going on forever. What makes me think heat is the water cooled Multistradas. If the cat is in place, black rear brake fluid.
That's some good info right there.
Haven't seen but a few MTS1200 myself.
Good ideas. I never thought about fluid analysis. I'll see who or what I can dig up.
Quote from: howie on September 30, 2019, 04:45:14 AM
Something definitive would be nice. This black brake fluid discussion a has been going on forever. What makes me think heat is the water cooled Multistradas. If the cat is in place, black rear brake fluid.
Agreed. The MTS rear brake has been another source of speculation. A number of folks on the MTS forum have still encountered the issue with cat removed. As a result, the ABS unit has been suspect. Though the front brake fluid is not prone to the same degradation as the rear, though it obviously goes through the same ABS unit. Folks seem to have good luck with the spendy Castrol SRF and its higher boiling point, though.
My issue right now though is clutch going bad after 250-300 miles, fixed by bleeding the MC each time. Slave was removed from the equation with new Oberon unit. OE rubber clutch line could be a source, or leak somewhere involving the MC.
I've never had a clutch MC apart to know if the black residue on the piston/seals is normal or excessive. Since the seals
appear to be okay, I started to wonder if the residue was sufficient to allow air into the system. Visual inspection overall hasn't yielded anything, so I'm left to guess and replace what I can.
Will keep updating. Thanks again for the insights and discussion [thumbsup]
Quote from: Speeddog on September 23, 2019, 09:49:14 PM
I'm pretty sure a banjo bolt pressure switch would trigger at too high a pressure to work for the clutch.
~~~SNIP~~
Not sure where I pulled that idea from. [roll]
Just tested one mounted on a clutch and it switches at low effort.
Should be fine.
A mate has the RCS masters on his Superlight and they work great. The adjustable pivot ratio feature lets you fine tune them for feel. It meant buying the bracket kit for the resi's or making some. Thinking about it, I don't know if I'd want the m/c supporting a bark buster anyway.
I ended up returning the RCS levers. Nice hardware, as I said, but fitment issues were bothersome enough.
Repair kit arrived yesterday and the piston is identical. Funny part is that the $20 kit contains the $25 dust seal [bang]
Info about the recall, parts involved, and rebuild instructions here, in case anyone needs it or is interested: https://static.nhtsa.gov/odi/rcl/2017/RCSB-17V812-2711.pdf
I hope to get everything back together this weekend. Temps dropped drastically coupled with early snow, so I'm not sure if I'll be able to get the miles in to fully test. We'll see.
Well... I wasn't as clever as I thought I was. While it appeared identical, the piston was just hair too large and would not fit.
So, I gave everything a good cleaning, reassembled and bled with fresh fluid. I'm hoping that will return function to normal. I was able to use the new dust cap, at least. :-\
Ah, the recall. What is the piston made of? If it is plastic Ducati has to fix it for free regardless of...well...anything.
Quote from: howie on October 19, 2019, 09:27:18 PM
Ah, the recall. What is the piston made of? If it is plastic Ducati has to fix it for free regardless of...well...anything.
The original was made with PPS (Polyphenylene Sulphide) and based on the documentation is light brown in color. The replacement is aluminum. The existing piston appears to be aluminum, same as the replacement. Seems they switched in later model years.
https://static.nhtsa.gov/odi/rcl/2017/RCSB-17V812-2711.pdf
In that case the piston can be used again. The problem would be sourcing proper seals. You might have some luck with other brands using that master.
Well... I'm puzzled. I finally broke down and bought a used MC off of a '14 MTS (2010-13 MC were all superseded by '14).
And I've got the same problem. Rode fine for about 300 miles, then next to zero friction zone with clutch grabbing just a hair off the grip.
So I've replaced the slave with a new Oberon unit, replaced the MC. The only two remaining options I can see are that 1) the line has a pinhole somewhere, or 2) my technique somehow is leaving an air bubble somewhere/somehow.
Any other thoughts or suggestions?
The reservoir, the hose, the plastic fitting, and the rubber biscuit it fits into, all of those can leak air in and not leak fluid out.
Quote from: Speeddog on June 14, 2020, 10:01:17 PM
The reservoir, the hose, the plastic fitting, and the rubber biscuit it fits into, all of those can leak air in and not leak fluid out.
Right. Those parts were all included with the MC, so I replaced the whole assembly. That's not to say the replacement parts can't be the issue, just not sure.