Mushy Front Brake Syndrome - I may be on to something...

[Journeyman]

Had one of those random 2 a.m. ideas. I've had somewhat soft front brakes for some time. What if I strapped down the front brake lever overnight and then, before releasing it, I bled the MC?

First of all, in my experience the whole idea of strapping the brake lever overnight is complete BS. It feels great for about two or three pulls and then returns back to soft (we're talk'n brakes here),in no time at all.

But, what if instead of just releasing the pressure, on the lever, what if I gave that air an escape? On the 2.5s that would be the bleeder screw located inside the front brake and clutch MCs.

Well, when I opened up that screw I hoped to see a surge of air bubbles. I didn't, but the brake was really firm. OK, so I figured it would revert to soft again pretty soon but, so far,
surprisingly, it hasn't.

I'll need to see if it slowly goes flacid (still talk'n brakes here...). If so, I'm going to suspect either a MC problem- btw, there is no rebuild kit- you have to buy a complete new MC or, if I'm lucky I can get away with just rebuilding the calipers.

The fact that it has held firmness this long though is pretty encouraging. I'll report back in a few hundred miles with an update.

 

[imcool]

Had one of those random 2 a.m. ideas. I've had somewhat soft front brakes for some time. What if I strapped down the front brake lever overnight and then, before releasing it, I bled the MC?

First of all, in my experience the whole idea of strapping the brake lever overnight is complete BS. It feels great for about two or three pulls and then returns back to soft (we're talk'n brakes here),in no time at all.

But, what if instead of just releasing the pressure, on the lever, what if I gave that air an escape? On the 2.5s that would be the bleeder screw located inside the front brake and clutch MCs.

Well, when I opened up that screw I hoped to see a surge of air bubbles. I didn't, but the brake was really firm. OK, so I figured it would revert to soft again pretty soon but, so far,
surprisingly, it hasn't.

I'll need to see if it slowly goes flacid (still talk'n brakes here...). If so, I'm going to suspect either a MC problem- btw, there is no rebuild kit- you have to buy a complete new MC or, if I'm lucky I can get away with just rebuilding the calipers.

The fact that it has held firmness this long though is pretty encouraging. I'll report back in a few hundred miles with an update.

cant we find rebuild kit with specs, once you open it?

 

[atomsplitter]

I had that 2 AM bulb go on when I was trying to bleed by son-in-law's front brakes on his 2010 Speed Triple. I went out to the garage and puked a bubble out from the lever perch bleeder nipple and the fronts were rock solid after. You have to bleed that nipple anytime you dork with brake fluid changes.

 

[mo8414]

Hopefully it stays good. Brake issues would drive me crazy. I've been lucky so far and haven't had any issues.

 

[Journeyman]

cant we find rebuild kit with specs, once you open it?

I've put quite a bit of time into it, including contacting Brembo. The calipers are used on other bikes, but the MC is different and supposedly the internals. Now their is an "upgraded" MC you can get for even more money. I just want the darn piston and seals kit.

You can find out more from an earlier post on did specifically on that here....

Front Brake/Clutch Master Cylinder Rebuild Kit?

I've scoured the web and don't see one for the 2.5s. It looks like you have to buy the complete front brake assembly. Has anyone come across an aftermarket company with a rebuild kit for these bikes?

www.r3owners.net

 

[imcool]

I've put quite a bit of time into it, including contacting Brembo. The calipers are used on other bikes, but the MC is different and supposedly the internals. Now their is an "upgraded" MC you can get for even more money. I just want the darn piston and seals kit.

You can find out more from an earlier post on did specifically on that here....

Front Brake/Clutch Master Cylinder Rebuild Kit?

I've scoured the web and don't see one for the 2.5s. It looks like you have to buy the complete front brake assembly. Has anyone come across an aftermarket company with a rebuild kit for these bikes?

www.r3owners.net

is it possible that you can provide some measurements of the seals if you have it opened it already ?

I have found following parts specifically for brembo master cylinder rebuild

below is your MC icture from earlier/other thread,

 

[Journeyman]

That clutch MC was taken apart about 25K miles ago, but here is the photo. I tried what you're doing (but please don't stop) and couldn't find a piston that looked the same....

 

[imcool]

That clutch MC was taken apart about 25K miles ago, but here is the photo. I tried what you're doing (but please don't stop) and couldn't find a piston that looked the same....

the piston I found looks same to the one you have in your photo, it has seals on it so probably thats why its looking different? but it looks same to me
may be I am wrong but people who bought this piston are saying that 'it fit their brembo MC'

 

[Journeyman]

Close, but I think not quite the same. It's hard to be 100% sure though. One thing is the notch on the left end.
If you give it a shot and can confirm that would be golden. I'd buy now....

 

[imcool]

Close, but I think not quite the same. It's hard to be 100% sure though. One thing is the notch on the left end.
If you give it a shot and can confirm that would be golden. I'd buy now....

there is notch but i think the notch is definitely the *retaining ring*

in your picture where you have MC disassembled, you have 2 retaining rings , so the one you marked above in your photo in white is I think definitely the smaller retaining ring.


check another picture I found

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