Ducati Monster Forum

I noticed that my front wheel on my 1198 is almost imposable to spin after I come in from the track.
seems to be my calipers locking the wheel........any ideas  ???

Well used brakes pads that are pushed far out by the pistons and pressing on the disc(s) ???

Just fitted new pads, the OEM ones were shagged after 1200km.

did you fit the right ones?
a lot of brands offer different thickness of material dependant on what rotor you are using, chances are you have fitted the thicker pads by mistake.

paul.

I would say a new set of seals for the calipers

The Pads fitted came from my D16 which were used for 4 or 5 track days ,I do recall the 1198 starting to grab with the OEM pads just before i changed them.
I'm thinking the fluid is getting hot and expanding in the lines.I have changed it once but only with standard DOT4.
May look at Motul 660 factory line has a 325℃ boiling point .

looks like they're the same calipers, therefore the same pads (oe) between the two bikes, did you fit left inside to left inside, left outside to left outside etc? the uneven wear from the D16 will cause them to not sit right unless they go into the caliper in the correct sequence.
doubt the fluid is the problem, change it regularly though, especially if you do track days but remember, the higher the DOT rating the more hydroscopic it is and therefore requires changing very regularly to avoid corrosion damage to components from water in the system.

paul.

No sticky slides or pins ??

Cant say I did the right sequence as they were in the tool box, so they would have gone in randomly.In any case the problem was evident before I installed the new pads .

Nah gave them a clean before fitting the new pads,Also pushed the pistons back with out a problem. I must admit I have been changing them on a front stand and not a head stock stand and not setting the front down before nipping everything up, This could also be the issue.

That assembly procedure shouldn't really matter.
Check the holes where the pins go aren't binding, they may be elongated or out of round ???
Can't be much more than that.

What "Holes" and "Pins" we talking about  ???

The ones that hold the pads in

It dosen't have pins it has springs on top  ???

It dosen't have pins it has springs steel retainers on top  ???

(http://www.motowheels.com/italian/images%5Clg305591393.jpg)

how old is the fluid, hot brakes, moisture in fluid, expansion, locked brakes.

It has done  7 or 8  track days , with in this time a set of OEM pads.

If you take the caliper off and push the pistons back without the retainer springs in do the pads slide freely ??

Any burrs on the pads ?

Retainers bent ??

Air in the lines will expand a lot when hot too

Yep nice and free ,Can't see how the retainers would have an effect on the pads in that direction if it was bent .It is only to keep the pads in the caliper and not as a slide.

I think I'm heading down the expanding fluid/moisture/air direction  ???

undo the grub screw locking the m/cyl piston pushrod adjuster and wind it out a turn and see if that changes anything.

Tried that , I have these leavers fitted to it with all types of adjustments,The red nob reduces the pressure on the piston rod .
(http://www.carbon-imports.com.au/images/Archimedes-Levers.jpg)

Can't see it being the fluid, but hey there's always something to learn even after years  in the automotive industry !

Yeah,  sorry, I never asked, is it one or both calipers seizing? Hard to tell I know, but aids a lot in the diagnosis.

Sold a bike to a guy once ,an Aprillia RSV. 20 minutes later he rings me telling me hes stuck on the side of the road and the back wheels locked.

He called me back after a few days,turns out he was riding the rear brake and locked the wheel when the fluid expanded.

Be difficult to find out  if it was only one caliper ???

Heat can do strange things

If you've got it up on a stand, put some pencil marks (or Bearing blue or texta, but not too much) on the disc, get a mate to turn the wheel and
listen at the caliper to see if you can tell by the sound, otherwise check to see if the pencil /bearing blue marks have rubbed off.

OK Dock I have applied my almost incomparable mechanical and motorcycling knowledge to your query and identified the problem and offer a solution.

It would seem your poor tortured bike is mounting a protest at the hard life it has led. So the most obvious solution is to find an appropriate home for it as it is like a little puppy that can't be cared for appropriately.

We can offer this poor unfortunate a loving home where it will be surrounded by friendly faces that will not intimidate such a youngster. I can only assume you are just days away from posting up 'free to a god home' ... and when you do remember us and this post, we will do what we can to help.

Oh yeah and the added advantage is I could ride the bike with the handbrake on and probably not realise its capabilities have been restrained.

Everybody wins!

Her working days as a track wench are not over yet Betty,She'll be ridden hard for some time yet as was the R1 [evil] .But when she is ready for pasture I will keep you in mind. [thumbsup]

love to see dribbles of information when you're trying to help someone, for make the beast with two backss sake vince! tell us you have changed levers and pads and they're useed, and you didn't mark what place they were in on the other bike and it was doing it before you changed the pads over etc. etc.
are those fancy levers set correctly, the old type with the screw in the end were notorious for blocking the bypass port in the m/cyl when wound in too far causing a build up in pressure and locked brakes. yeah yeah, i know, you know what you're doing and it can't be that but your brake fluid theory is bogus. there's no way brake fluid will expand when it gets hot, it's designed to do exactly the opposite and being a serious safety item (brakes!) it just wouldn't be acceptable to allow that under any circumstances.

paul.

+1 [thumbsup]

Ok some more information dribble.

After the calipers cool down, Hey presto it all comes good. How do you explain that, i have no idea other than the expanding and contracting of something  ???

spoke to somdumguy today he say "danielson"  in some cases there is small air bubbles trapped in the calipers in areas higher that the bleeder or brake line connection,which can cause this problem.

The most common way of getting air into your system is pushing the pistons back to fast , this mixes small air bubbles in with the fluid as it returns to the reservoir ,When you pump your leaver to take up the slack after fitting new pads you send it back down the line with the fluid.  ???

 

well bleed your brakes properly then!

Going to try some Motul 660 factory line .

what's the DOT rating of that?
the higher the dot the faster it absorbs moisture and the more often you will need t replace it. [thumbsup]


paul.

Im going for DOT4

RBF660 FACTORY LINE
 
100% Synthetic Racing Fluid – DOT4
Very high boiling point: 325℃/617°F
Very high wet boiling point: 204℃/400°F.

SPECIFICATIONS
 
Feature 100% Synthetic Racing Fluid. Polyglycol bases.
 
SAE/DOT Standard FMVSS 116 DOT 4/ SAE J1703 & J1704
 
Specification ISO 4925
 
http://www.motul.com.au/product_line_up/fork_brake_others/others03.html (http://www.motul.com.au/product_line_up/fork_brake_others/others03.html)

I still can't see it being the issue

Hey why you want brakes anyway, they just get in the way of speed  [evil]

after a session put a piece of clear hose on a bleeder, hold it vertically and crack the bleeder.  fluid comes out quickly = fluid pressurisation problem.  it will run fluid out slowly due to the level difference, but if it shoots up the tube it's pressurising.  close the bleeder and try moving the bike too.  make sure nothing is blocking the piston from coming as far as as it would without a lever fitted.  the only way it can pressurise if is the compensating port is blocked.

One question, did just changing the pads fix the original problem ?

top advice, i suspected the levers not being set right as the culprit when vince posted the pic of them, excellent way to diagnose it brad.

paul.

Or was something else done at the same time ?
Or did all this start after the levers were fitted ?

Started with in a few track days and got worse still as a standard bike.Its only when i fitted the last set of pads that it is so bad that the front wheel need a fair amount of force to get it to turn.basically i need one hand to turn the wheel to fit the tire warmers.But as stated before after a short while it all sorta goes to back normal, just a little drag.

Some extra dribble, cuz i know how much Loony hates it.

The rotors are blue/black not on the ends just on the faces.I have also noticed that some of the racer guys have the same problem ,just a little less than mine.waiting for Craig McMartin to give me a buzz with some info.

BR Vince

Just found this. [thumbsup]

http://174.143.221.140/ME2/Audiences/dirmod.asp?sid=&nm=&type=news&mod=News&mid=9A02E3B96F2A415ABC72CB5F516B4C10&tier=3&nid=7A529F8E7D7748A992DC1F09C716CA00&AudID=7D8998E6B4B64029B8320B216F4F3861 (http://174.143.221.140/ME2/Audiences/dirmod.asp?sid=&nm=&type=news&mod=News&mid=9A02E3B96F2A415ABC72CB5F516B4C10&tier=3&nid=7A529F8E7D7748A992DC1F09C716CA00&AudID=7D8998E6B4B64029B8320B216F4F3861)

My old Kawasaki is a bit like this. Could it be wheel bearings?  ???
Kaz.

so after all the dribble and name dropping vince ;D, did you get it fixed mate?


paul. [thumbsup]

Yep changed the oil with Motul 660 and the problems gone,was also able to shave 2 seconds of my P/B [thumbsup]

2 seconds? what did you shortcut turn 9 or something?

Nope,Just got some feelling in the front again  [thumbsup]

2 seconds is a massive improvement!!!!!   :o

Ita

more likely his torn heartlidge is on the mend, or he swallowed a 20kg bag of cement and hardened the f*&k up

That's really well done, Dockstrada.  Ignore the other guys, they're just jealous.

 ;D

he can't ignore me - well he can try, but it is pointless...

Not jealous SJ...  But knowing how hard it is to find 2 secs a lap I would say stunned....

Ita

Having now been around Eastern Creek on a bike with more than single digit horsepower I feel more than qualified to reply [evil]

I'm pretty sure that it is easy to find a measily 2 seconds ... losing 2 seconds may be an entirely different matter [laugh]

I may just have lowered myself to a whole new level of self amusement.