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Sorry to revive this thread, but after your thoughts......

27th January 2021; MY19 Dragster went to dealer to have rear brake service bulletin carried out. Good rear brake was achieved. The bike sits in a heated garage on paddock stands. Occasionally when I went into the garage I would check the rear brake, whilst he bike sat there, not being used. Sure enough, the brake pedal got longer and longer (still working but had to press down further and further).

31st May 2021; want to go for first ride of the year, so thought I would follow the service bulletin to get a good pedal back. Unfortunately, I now have no pressure at all and brake is not working at all. Will not even get any pressure when the pedal is pumped. Strange thing is, with the reservoir cap off, you can pump the pedal and the fluid level goes down (still no brake), stop pumping and the fluid level returns to the high mark.

Any ideas? I can only think that the master cylinder is faulty?
 

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Sorry to revive this thread, but after your thoughts......

27th January 2021; MY19 Dragster went to dealer to have rear brake service bulletin carried out. Good rear brake was achieved. The bike sits in a heated garage on paddock stands. Occasionally when I went into the garage I would check the rear brake, whilst he bike sat there, not being used. Sure enough, the brake pedal got longer and longer (still working but had to press down further and further).

31st May 2021; want to go for first ride of the year, so thought I would follow the service bulletin to get a good pedal back. Unfortunately, I now have no pressure at all and brake is not working at all. Will not even get any pressure when the pedal is pumped. Strange thing is, with the reservoir cap off, you can pump the pedal and the fluid level goes down (still no brake), stop pumping and the fluid level returns to the high mark.

Any ideas? I can only think that the master cylinder is faulty?
Get use to it. Common issue with the rear brembo that's inverted. Mine they replaced master just to try it. Same issue went limp. The rear inverted brake will be become part of your maintenence and actually ducati does not warranty this issue as well. I have the 21 v4s street fighter same issue but my dragster was 100 times worst for some odd reason. Sold the mv became to many issues unfortunately:( . For now mv is covering it under warranty buy t.be prepared for them to start denying it.
 

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Discussion Starter · #183 ·
Yes. The probable solution is in this thread. I have not carried out my own modification yet, but when I am able it will be done. Physics works.

Raise the height of he rear master cylinder's fluid tank (or level) higher than the ABS unit.
 
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One month out from performing the service bulletin procedure, riding every day it doesn't rain and the rear pedal is firm and ABS is working.
 
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I plan to raise the rear master cylinder on mine and add bleed nipples to the abs unit. Looked at the latest Superveloce , basically a F3 , there was a bleed nipple fitted on the abs unit ?
 

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Sorry to revive this thread, but after your thoughts......

27th January 2021; MY19 Dragster went to dealer to have rear brake service bulletin carried out. Good rear brake was achieved. The bike sits in a heated garage on paddock stands. Occasionally when I went into the garage I would check the rear brake, whilst he bike sat there, not being used. Sure enough, the brake pedal got longer and longer (still working but had to press down further and further).

31st May 2021; want to go for first ride of the year, so thought I would follow the service bulletin to get a good pedal back. Unfortunately, I now have no pressure at all and brake is not working at all. Will not even get any pressure when the pedal is pumped. Strange thing is, with the reservoir cap off, you can pump the pedal and the fluid level goes down (still no brake), stop pumping and the fluid level returns to the high mark.

Any ideas? I can only think that the master cylinder is faulty?
My bike is a gen 2 F4. As soon as I get back from a ride the bike goes on a paddock stand and I use a bungee to wrap round the rear brake lever tied to the paddock stand. After about an hour I can spin the rear wheel, I pump the lever a couple of times and the brake is strong again. The brake is good enough on rides to active the ABS and I have been doing this ever since I bought the bike. This was a tip from the dealership.
 

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Discussion Starter · #187 ·
The F4 has a very different t configuration from the three cylinders. This thread addresses the triples’ issue
 

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By the way, on my 2018 Dragster RR the rear brake lost pressure this morning. So, I am planning on third bleed/maintenance with my Houston, TX mechanic. He said he has a "better procedure".
 

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My bike is a gen 2 F4. As soon as I get back from a ride the bike goes on a paddock stand and I use a bungee to wrap round the rear brake lever tied to the paddock stand. After about an hour I can spin the rear wheel, I pump the lever a couple of times and the brake is strong again. The brake is good enough on rides to active the ABS and I have been doing this ever since I bought the bike. This was a tip from the dealership.
Do you check the fluid level in the reservoir when performing this procedure?
 

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Do you check the fluid level in the reservoir when performing this procedure?
I don’t. I do check the levels periodically. I also do activate the ABS using the rear brake as I initially ride off and when sat at traffic lights I apply the rear brake. Since doing this I haven’t had a problem with the rear brake.
 

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I was hoping not to face this issue but unfortunately I did. Having roughly year old bike since it was manufactured September 2020, now having 4000 kms on the clock.

Noticed after each ride that rear brake pedal is going steeper and steeper and last trip was not funny while going down serpentines and would like to have rear brake available to balance in tight corners. But luckily, I was able to recover in pretty easy way by performing bleeding using proper vacuum bleeder (powered by pressure air). I just used straight forward way, bleeding ~ 0.5 ltr fresh fluid by continuous process: Vacuum on the the nipple, caliber in its normal position, opening the screw suitable amount and then re-filling reservoir at the same time.

My idea was to create strong flow of the fluid which will take "trapped" air away from ABS-module. You need to be carefully, flow was actually quite fast and at the end you need to close the screw in the caliber timely manner that reservoir is not sucking any air.

I would guess that issue is the location of ABS-pump as stated several times. When it's located at highest point, it will have low "negative" pressure for pump & solenoids. Knowing their construction & sealings, they will pass air in over the time. Brake-fluid having much higher viscosity than air, it won't get out but air molecules will get in.

Someone was already pointing out good proposal; Getting weight hanging on the pedal while bike standing on the charger. Time will tell...
 

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MV is negligent ignoring this issue. They need a recall kit to move the tank above ABS unit.
 

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MV is negligent ignoring this issue. They need a recall kit to move the tank above ABS unit.
Same issue with my 21 ducati streetfighter v4s and my 21 ducati 950s along with my 18 mv rr dragster it's all platforms ducati treats the issue as a maintenence item at customers expense price you pay for having exotics I take it at this point. There all inverted brembo's :( my fighter i have to bleed both brakes about every 750-1000 miles to maintain high performance braking.downside to having Italians
 

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Earlier someone mentioned the upside down caliper and bleeding. I did this conversion on another bike. I got rid of my stock, cheap caliper and upgraded to a Brembo p32 and a custom carrier. It looked amazing.

I bleed the brake...nothing. Bleed more. Nothing. Now, you guys know a rear brake holds very little fluid. Im worki png on a brand new container of fluid. Enough to do a full motorcycle, and clutch, 3 or 4 times. Im near the bottom of the container and still have nothing. I thought I was crazy, stupid , or a mixture of both.

As I was ready to give up, I remembered that I had a cheap, Harbour Greight bleeding machine that hooked to my air compressor. I connect it and pull the trigger. I pull its lever and nothing but air comes out. One more pull, and theres my fluid. The brake was now working and was an excellent upgrade.

I think you guys are on to something when you talk about inverting g the caliper for bleeding, or usi g one of these machines.
 

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Discussion Starter · #196 ·
The manual tells you to remove the caliper and invert it to bleed....why wouldn't you?
 

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Turismo Veloce Rosso EAS -20
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MV has added bleeding nipple on ABS-pump as well, as pic below. Those Blue & Red-hoses are for Rear-brake. Would guess, used when building / re-building bike but luckily didn't need to remove farings & lights to get access.

488504


And bleeding-machine itself as below. This will require some amount of compress air but works great. And would say as a must, otherwise impossible to get real flow for the fluid.

488505
 

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Don't run those pneumatic bleeders on more than 90 psi. 60 would be better. Over 90 psi the velocity of the fluid will start cavitation in the hoses and after you finish the lever will get mushy again in a short time as the micro bubbles caused by the cavitation coalesce.
 

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So I recently went through this with my new(ish) 2021 Superveloce. Brake was completely fine for a few months, thought I had dodged a bullet, then it got all mushy. No amount of "regular" bleeding seemed to help. I'd maybe get a tiny bit of pressure that would then disappear right away.

Reading through here I noticed three things people seem to say help:
1) Remove and invert rear caliper, then bleed
2) Bleed from the ABS pump
3) Relocate the fluid reservoir to above the ABS pump.

I decided to try all three, since I was getting ready for a 600 mile trip and didn't have time to try each one alone.

I relocated the reservoir, then bled from the ABS, then bled the inverted caliper.

So Far, the brake is hard as a rock and works about as well as a rear brake on a sportbike could work.

It does make my inner engineer tingle knowing that gravity is helping the reservoir apply positive pressure on the whole system while it sits there.....

Got some cheap ugly hose from NAPA, will order something nicer and re-do it at some point. The reservoir I just zip-tied under the passenger "seat." I'll make a bracket for it someday, too, but it's fine for now. Can't get the ABS pump cover back on... not sure what I'll do about that. Maybe get a cheap carbon fiber one and hack it to fit around the hose.

Or, I'll just delete the ABS entirely and put a Brembo front MC 😈
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e order a cheap
 

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I visited dealer about 2 weeks ago to get my completely gone rear brake fixed (20MY Dragster), and they said MV has decided to stop covering warranty for the rear brake issue after 1 year, at least here in Germany. So I had to pay to get it fixed, and how is it in other countries?
 
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