Problem with brakes or normal?

metroplex · May 30, 2011, 09:45:43 AM

I noticed that on my 696, the front brake lever remains stiff if I do quick stops where I sort of jab the lever. If I progressively squeeze the lever slowly to come to a stop, the lever will squish down to the point it will touch my 2 other fingers. Is this normal? I read a Cycle World review that complained about the brakes on the 796 being too progressive and was curious if this is the effect they are talking about. I plan to do a full flush with fresh DOT 4 brake fluid.

Howie · May 30, 2011, 09:57:27 AM

Hard to say without seeing the bike, but it seems kike bleeding is in order. If you pump the lever and the brakes feel better, you got air.

metroplex · May 30, 2011, 09:59:48 AM

It always felt fine if I jabbed it down to do a quick stop. If I slowly/progressively squeeze the brake lever while the bike is slowing, it will get softer eventually and it doesn't seem to slow it down fast enough.

The service manual doesn't quite say, but do I want to max out the clutch fluid level like the brakes (fill it up to the brim or the max line) or will the clutch fluid overflow as the clutches wear out?

Howie · May 30, 2011, 10:58:07 AM

Quote from: metroplex on May 30, 2011, 09:59:48 AM
It always felt fine if I jabbed it down to do a quick stop. If I slowly/progressively squeeze the brake lever while the bike is slowing, it will get softer eventually and it doesn't seem to slow it down fast enough.

The service manual doesn't quite say, but do I want to max out the clutch fluid level like the brakes (fill it up to the brim or the max line) or will the clutch fluid overflow as the clutches wear out?

Your description does no sound like your brakes are operating properly, but then again, since I can't experience the symptom... One thing you can do is take a trip down to the dealer and see how a bike on the floor feels. Also, if your bike is still under warranty you should have the dealer write up a repair order and take a look. Bleeding won't hurt unless you do something wrong. Also look for small leaks.

No, do not overfill, and there is no benefit to be had plus need room is needed for for expansion, and as your clutch wears fluid level will rise.

DarkStaR · May 30, 2011, 11:08:45 AM

It feeling more firm when you jam on it seems normal from my experience, but not so much it requiring that much more lever travel when not.

metroplex · May 30, 2011, 01:39:37 PM

Yeah, if I jammed on the brake lever (grabbed it) to do a quick stop in a parking lot - it will feel very stiff and the bike will stop.

I experimented by progressively squeezing the brake slowly and noticed that it didn't stop as fast as the lever got closer and closer to my other fingers.

I decided to go ahead and do a full bleed/flush of the brakes and clutch with fresh DOT 4. The clutch seems to work fine (always worked fine) and the front brake lever still feels about the same but I didn't take it for a road test.

The strange thing is that my rear brake now squeels. The old fluid looked brown/dark tan from just sitting in the dealership for nearly 3 years. The new DOT 4 looks very light yellow, like the new 1198/848/Diavel/1100 Evo bikes sitting in the dealer. But even when stopping the bike while moving it around on leg power causes the rear brake to squeel. It didn't seem to do this before I bled/flushed the rear.

Cloner · May 30, 2011, 07:29:36 PM

Brakes that are "too progressive" stop harder as the lever is pulled harder, but the result is a nonlinear increase in braking force for the lever pull. That is you pull x, the bike stops y. You pull 2x and the bike stops 3y. You pull 3x and the bike stops 6y.....for example.

Most riders prefer brakes with a linear feel. You pull x the bike stops y. You pull 2x the bike stops 2y. You pull 3x the bike stops 3y. Some riders prefer firm initial bite, some don't, but every rider I've met prefers a linear reaction.

What you're talking about sounds like a small amount of air in the lines. Look for air trapped in high spots above bleeders. Ducatis are notorious for trapping a small amount of air in the banjo bolt that attaches the brake lines to the master cylinder, so if you can't find it elsewhere, look there.

metroplex · May 31, 2011, 01:37:30 AM

I just bled and flushed the entire system using fresh DOT 4. I tried using my Mitvac but it wasn't working as consistently as I'd like so I ended up using the lever to push out the fluid. I didn't get an opportunity to test it yet, but the lever feels firm just testing it in the garage.

How much fluid do I want to keep in the reservoir? The service manual says MAX is to the brim, but if I do that it just spills all over the place. When I popped the cover for the first time, the fluid was just over the sight glass.

Howie · May 31, 2011, 03:31:59 AM

Quote from: metroplex on May 31, 2011, 01:37:30 AM
I just bled and flushed the entire system using fresh DOT 4. I tried using my Mitvac but it wasn't working as consistently as I'd like so I ended up using the lever to push out the fluid. I didn't get an opportunity to test it yet, but the lever feels firm just testing it in the garage.

How much fluid do I want to keep in the reservoir? The service manual says MAX is to the brim, but if I do that it just spills all over the place. When I popped the cover for the first time, the fluid was just over the sight glass.

The fluid needs to be over the middle of the site glass. If you just fill close to the top of the brake reservoir with the bike on the sidestand and to t5he middle of the clutch fluid reservoir with the bike vertical you will be fine.

metroplex · May 31, 2011, 03:38:23 AM

So on the sidestand, I want to fill all the way to the brim?
If I use a rear stand, I want to fill it up just over the sight glass or mid-way in the reservoir?

Howie · May 31, 2011, 03:45:26 AM

Midway on the rearstand will be fine.

metroplex · May 31, 2011, 03:48:06 AM

Ok, I'll check it again. I used my rear stand yesterday and filled it just over the sight glass. But I was wondering if I should fill it high enough that it overflows when I close the cap.

Howie · May 31, 2011, 04:02:49 AM

Quote from: metroplex on May 31, 2011, 03:48:06 AM
Ok, I'll check it again. I used my rear stand yesterday and filled it just over the sight glass. But I was wondering if I should fill it high enough that it overflows when I close the cap.

No! You need room for expansion. No room, the fluid gets hot and expands resulting in self application of the brakes. Not to mention brake fluid destroys paint and some plastics. Just over the site glass if fine. Then, if the level falls below the middle of the sight glass top between services, top off and check for leaks.

metroplex · May 31, 2011, 04:07:06 AM

The last vehicle I had with these type of reservoirs was a 1981 Ford and it was a PITA to top off and check. I was expecting Ducati to use all of the plastic bottle reservoirs like on the rear brake.

I see two weep holes on each reservoir gasket, will excess fluid just seep out of those areas?

Munch · May 31, 2011, 12:47:43 PM

Check the black plunger like thingy in the reservoir, sometimes it flips inside out, and take up space in the reservoir...

News:

Problem with brakes or normal?