So i rebuilt the rear master and calliper as the bike had been standing for years and stuck on/ overheated on the bench and on way to mot test. Master and calliper rebuilt perfectly nothing wrong or blocked, only half mile in and started to bind again, used genuine parts and 600 racing fluid i have plenty of play in the push rod and master piston is returning as it should, i popped it on top of the disc to bleed and was spot on. I now have released a bit of fluid and possibly let a little air in to it, done 20 m and works fine, bit vague but doesn't overheat. Any advice appreciated, I'm baffled !!
Same here. I posted on your other threads the same issue I’m having currently. I’ve got a new caliper on, still binds, and about to fit a new master cylinder. Everything was fine until I put rearsets on and took the slack out of the pushrod.
Make sure the brake lever returns easily with no binding. You may need to make sure the pivot bolt is greased
The bike has been stripped/greased to an inch of its life, at a guess the fluid is getting hot from heat from the exhaust, expanding and applying pressure to pads. By incorporating a little air in to the system, the expansion is took up by the air pocket. I thought the expansion should go back up the little pot, but lid is sealed, I would think it could blow the lid off ?? Doing my head in. Caliper/master/linkage like new.
Forgot to say I had new pads too, it can only be the fluid not expanding up the filler pot. Only one hole in the master,fill/return so if it’s filling it should return. I will remove lid and compress pistons to see if it does.
Do you have aftermarket rear sets fitted? Ive had this on other bikes with non standard rear sets (had it with a a/m front lever too) the lever design can make the brakes drag ever so slightly until it gets hot and binds.
@P1mao What is happening is that you are resting your foot on the rear brake pedal. The pads are dragging on the rear rotor and overheating.
i'm not going to jump to conclusions like I see a lot of people doing, but there's a chance that this is not enough slack at the rear brake master cylinder pushrod again, there are several threads already on here covering this and sometimes in extreme heat the play needs to be even more than recommended by Ducati. Of course there are several other possibilities, another one for example is if the reservoir cap is unable to allow air travel in either direction.
Easy way to tell if it's a free play issue, take the rod right off so nothing can act on the system and go for a ride. If all good then the problem is to do with the rod and its set up, if the problem is still there then it's in the hydraulics.
Not the Rod, Mine did it running the bike up on the stand (hence stripping and rebuilding calliper and master) as above blead it again and removed some fluid from reservoir to allow for expansion. I will inspect the cap tomorrow Thanks
Had a quick look over the brake today, not tried it, but without flipping it upside down to blead it’s spongy, if I press hard enough it will touch the fairing. This isn’t right ! The only other thing I changed was aftermarket pads, these seem much thicker , I’m thinking of binning them and going back to standard Brembo before I test it.
I was referring to pads with the overheating issue, every time I have blead it so it’s rock hard, it overheats. I might flip it,bleed it and pop in genuine pads.
The only way I have found to bleed my rear on 916 was to remove the thing entirely, hose and all, and bleed it with the caliper in the air. This was due to numerous mot fails where by the time i got to the test station the damned thing wasnt working again. And again. So I resorted to this. I never had this issue on my 1198 nor my 1299 but my goddamned 916 is prissy and demands special measures. Good luck on this P1 as I know how infuriatingly frustrating this can be.
If there was air in the system , wouldn't that mean the opposite ? I.E. brakes don't work. Assuming the pads are free to move (clean slides in the caliper) and the pistons are free (also clean) then the brake being on means there is pressure behind the piston. if nothing is jammed in the caliper then the pressure has to come from the master. That could be a seal kit or sticky internal slide or the pedal is keeping it on. I think there is a spring inside the master to help the slide return , it's feeble and prone to corrosion if I remember. Worth a look ?
