Lost my rear brake today :(

[Hossman]

New to the forum!! 03 XB9SL with 26k on the clock. I’ve had the bike for 3 months and I just found out from the previous owner that he never bled the brakes since buying it, brand new. He was very diligent in other manners of maintenance. This bike runs like a top, even in this cold weather. I did some DIY maintenance on it today and now am regretting it, unfortunately.

I was bleeding the rear brake earlier today and I believe I seized the master cylinder. I can bottom out the pedal without any fluid coming out when I crack the bleeder valve. Am I most likely correct in assuming I’ve seized it? How should I fix this? Buy the master cylinder rebuild kit? The extent of my DIY experience on autos and bikes is fluid changes. Maybe I should just take my XB to a mechanic... this is a serious bummer.

 

[user_deleted]

they're extremely tedious and tricky for a novice to rebuild. watch this vid. if it's beyond your capabilities and it probably is....then remove the M/C yourself, call around and find a local shop that will rebuild it for you.
FACTORY OEM REBUILD KIT PART # H0040.F
infinite number in system...list $16.49
surely the masses will chime in with jibberish re. seals....calipers....pistons....hoses...reservoirs ....fluids...God only knows.
your M/C is shot. period.

 

[Silverrider]

no shortage of them

https://www.ebay.com/sch/i.html?_fr...28&LH_TitleDesc=0&_osacat=6028&_odkw=buell+xb

 

[Chicknstripn]

My jibberish says go for the rebuild. It’s cheap enough that if you don’t succeed, at least you learn something.
AND when you buy a new master you’ll have spare parts.
Motorcycle maintenance isn’t rocket science. It’s more about confidence then experiance.
Go for the rebuild
If it doesn’t work or you screw something up, at least you didn’t pay some Ahole in a shop 60bucks an hour to come up with the same result.... .....you needing to buy a new master cylinder.

 

[nicholas900]

I rebuilt mine. Not bad to do. However I wonder if that's actually your issue. Do I understand this right?

-You had no issue with your rear brake. It worked fine.
-You decided to bleed out the old fluid as preventative maintenance . Now you have a problem.
-You are moving the brake lever to bleed. It travels through it's stroke but no fluid comes out of the bleeder on the caliper.

If you are pushing the pedal and it moves the plunger in the MC, it's not seized. It could have worn seals but...

I think the problem might be just how you are bleeding the brakes. Care to describe how you are going about the bleeding procedure? Might be as simple as not properly bleeding the system and having air in the MC.

 

[Hossman]

I rebuilt mine. Not bad to do. However I wonder if that's actually your issue. Do I understand this right?

-You had no issue with your rear brake. It worked fine.
-You decided to bleed out the old fluid as preventative maintenance . Now you have a problem.
-You are moving the brake lever to bleed. It travels through it's stroke but no fluid comes out of the bleeder on the caliper.

If you are pushing the pedal and it moves the plunger in the MC, it's not seized. It could have worn seals but...

I think the problem might be just how you are bleeding the brakes. Care to describe how you are going about the bleeding procedure? Might be as simple as not properly bleeding the system and having air in the MC.

I would pump the brake for a little to build up pressure. Then crack the bleeder valve while pushing all the way down with my hand. Once it bottomed out, I would tighten the valve and repeat. I was assuming I shoved the piston all the way to the top and it got stuck at the top. I would assume the spring inside the master cylinder would return the pedal to the top of its travel and the piston would stay stuck. I’ve never disassembled one, so I’m just guessing.

 

[nicholas900]

10-4. Yeah. If the brake lever is just floppy, that's what happened. The video posted above should get you through it.

 

[Hossman]

10-4. Yeah. If the brake lever is just floppy, that's what happened. The video posted above should get you through it.

Thanks! I suspect the fact that the previous owner never- and I mean never, used the rear brake and never bled the fluid probably excacerbated the problem. Do you think the method I was using to bleed the rear brake was not the best?

 

[34nineteen]

Thanks! I suspect the fact that the previous owner never- and I mean never, used the rear brake and never bled the fluid probably excacerbated the problem. Do you think the method I was using to bleed the rear brake was not the best?

Your bleed method was probably fine, but you probably had some crud inside the MC thats making the piston stick. There is a return spring, but its not the strongest. If you pull it and carefully disassemble, you can probably clean it out and bring it back to life.