Ducati.ms - The Ultimate Ducati Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
2,549 Posts
Discussion Starter #1
Well I have found the first small issue with the st and it comes in the form of excessive brake lever travel. I noticed it after picking it up but seems like it has become more prevelent or at least more noticeable as of late. I can pull the lever in 1/2-1 inch before getting some bite which I know is not correct. Its manageable but I find myslef having to consciously think a little too much about it and once applying front brake it does not have much feel causing it to lock up a tad to easy under hard braking because of the lack of linear feel.

I am going to pull the calipers later today and clean them up and see what the pads look like. From looking at them on the bike they appear to be pretty good yet but maybe a little cleaning will help. Might try a fluid change if that doesn't help. Fluid looks good and is at the correct level.

I mainly wanted to ask if there is any known issues with the master cylinder on these? (01 st4)

I've never had this style of Brembo levers before so I was looking at the adjustment and noticed the screw inside has a clear silicone or something inside with it (I am assuming to hold in place) Can these screws be adjusted and if so, do you need to silicone them again I assume. Any help would be appreciated. Thanks gents.........
 

·
Registered
Joined
·
339 Posts
Motard,

The early STs were known for "mushy" brakes. The brakes worked fine but the lever travel was excessive and feel was mushy. Some owners upgraded to a master cylinder with a larger piston (I put a Nissan on my '98 ST2).

The first step would be to buy some new fluid and bled the brakes per instructions that you can find by doing a search here.

What condition are your brake lines in? You might consider upgrading to braided stainless steel if you don't have them already. (They came OEM on the '02 ST4s, not sure about the ST4.)

If you break the seal on your OEM lever (it's hot glue) don't move the screw very far. You run the risk of blocking the return passage in the master. That could result in a locked front brake. A search should give you more details.

My '02 ST4s came with great brake feel. I haven't had to do a thing.

Jeff in Colorado
 

·
Registered
Joined
·
1,910 Posts
If you squeeze the lever a couple of times, do the brakes get firmer with less travel?

That would be an indication that a small amount of air is in the system. And air loves to get trapped in the banjo bolt.
 

·
Registered
Joined
·
2,549 Posts
Discussion Starter #4 (Edited)
If you squeeze the lever a couple of times, do the brakes get firmer with less travel?

That would be an indication that a small amount of air is in the system. And air loves to get trapped in the banjo bolt.
No I don't believe its air, they are just the same all the time pretty much. I can pump them up and nothing really happens. I'll try cleaning them up maybe and bleading the brakes soon and go from there. Might have to upgrade to bigger MC if needed.
 

·
Registered
Joined
·
3,903 Posts
Try pressing the brake pads back a bit (retract the pistons a little). Pump the lever repeatedly so the pad seat again. Repeat. Then try it and see how it feels. I notice mine always feels better when I R&R the front wheel. I press the pads back a bit to allow the calipers to fit back on easier. But when I'm done, the brake lever feels great again. But a few days later, and it's got more travel...about 1/2 way to the grip.
But even with this travel, it always has great stopping power.

Not sure what it is about moving the fluid backwards into the master cyl. that makes this feel better. I don't believe it's air, either, because the lever never feels mushy, and pumpumg the lever makes no difference.
 

·
Registered
Joined
·
2,549 Posts
Discussion Starter #6
Try pressing the brake pads back a bit (retract the pistons a little). Pump the lever repeatedly so the pad seat again. Repeat. Then try it and see how it feels. I notice mine always feels better when I R&R the front wheel. I press the pads back a bit to allow the calipers to fit back on easier. But when I'm done, the brake lever feels great again. But a few days later, and it's got more travel...about 1/2 way to the grip.
But even with this travel, it always has great stopping power.

Not sure what it is about moving the fluid backwards into the master cyl. that makes this feel better. I don't believe it's air, either, because the lever never feels mushy, and pumpumg the lever makes no difference.

Thanks stick, thats what I was going to try when I pull the calipers. My 06 Speed Triple had the same problem. Pull that calipers, clean them up and do a little reset and it was good again for a few hundred miles. That said if this is going to be an ongoing issue I will have to look into the MC upgrade as I really don't like the mushy feel. Its very wooden feeling after you get the slack taken up and leads to poor braking in my experience because its difficult to modulate (feel) the braking. I practice emergency (maximum) braking almost everytime I get on a bike and twice now I have locked up the front briefly which I never had a problem with on my other Ducati's. I am also running some old tires (Good tread) but the rubber has hardened I believe so this is not helping with max braking.

Anyway thanks again for the advice....always good to get multiple viewpoints.
 

·
Registered
Joined
·
1,910 Posts
I'd be willing ito bet that brake pad performance deteriorates as they wear. If the pads are thin it may be part of the problem, especially if you practice e-stops. If you replace the pads, scuff both sides of the rotors with an aluminum oxide 80 grit sand paper. Then clean the rotor surfaces with brake cleaner or IPA (rubbing alcohol).

Fully flushing the older fluid can also improve feel. Brake fluid is hydroscopic, it'll absorb moisture over time. If the moisture is in there long enough, it'll migrate to the lowest point, the bottom of the calipers and contributes to the mushy lever feel. Try tipping the calipers upside down when bleeding to get the moisture out. Then re-bleed, with the calipers in the normal position to re-move any entrapped air. Re-bleeding a couple days later can bring it back to primo form.

It's a lot of work, but it's definitely worth the effort.
 

·
Registered
Joined
·
407 Posts
brakes

I'd be willing ito bet that brake pad performance deteriorates as they wear. If the pads are thin it may be part of the problem, especially if you practice e-stops. If you replace the pads, scuff both sides of the rotors with an aluminum oxide 80 grit sand paper. Then clean the rotor surfaces with brake cleaner or IPA (rubbing alcohol).

Fully flushing the older fluid can also improve feel. Brake fluid is hydroscopic, it'll absorb moisture over time. If the moisture is in there long enough, it'll migrate to the lowest point, the bottom of the calipers and contributes to the mushy lever feel. Try tipping the calipers upside down when bleeding to get the moisture out. Then re-bleed, with the calipers in the normal position to re-move any entrapped air. Re-bleeding a couple days later can bring it back to primo form.

It's a lot of work, but it's definitely worth the effort.
Bleed them properly with Motorex DOT 5.1 fluid and they should improve.
 

·
Registered
Joined
·
2,549 Posts
Discussion Starter #9
Bled the brakes/clutch today + cleaned up the pads and still has the same feel as before. Might be just a tad better but not much.

The pads still look good, plenty left on them......

I'm wondering if going to a set of Pazzo's/CRG's with adjustability might help because the binders work fine once they start doing there job, I just don't like the amount of free lever travel before they start working. Thinking maybe adjustable levers might be the ticket. Any thoughts.........
 
1 - 9 of 9 Posts
Top