Intermittently my rear brake has been seizing up. If I pump it a few times it usually let's off. Now it locks up and then won't unlock the rear brake. If I break free the sensor that's screwed into it, then the brakes release. So I'm sure the problem is what I would call the rear brake master cylinder. Has anyone had this happen? Can I rebuild it or do I have to replace the entire assembly? Part numbers? Thanks for any help.
Rear brake locked up
- Thread starter arikam
- Start date
Help Support Buellxb Forum:
- Joined
- Jan 26, 2011
- Messages
- 1,899
Sounds like you have the wrong brake fluid in it...
Master cylinder part #H0205.1AA
I also have a used one if your interested...
Master cylinder part #H0205.1AA
I also have a used one if your interested...
I'll check the fluid. Brake was seized up when I bought the bike. It was somewhat abused. But it freed up then locked up a few different times. But in 4 months of driving it's only locked up 4 times but then released. Now it doesn't release. I'll take it apart and see what it looks like. And ill change the fluid. How much do you want for the used one shipped to 36305? Thanks for your help.
rchuff
Well-known member
That's 4 times to many. Need a new one or rebuild it.
nicholas900
Well-known member
ASB has a rebuild kit. It's cheap and easy.
If u need a quick fix but by no way a proper fix take it off and squeeze the plunger of the caliper all the way in and push the pedal back out then squeeze the plunger back in...its worked on long rides for me on my KTM till I got a new one..
.also check to make sure the pedal moves freely. I powdercoated mine and forgot to clean out the inside of the hole which led to a sticky brake
.also check to make sure the pedal moves freely. I powdercoated mine and forgot to clean out the inside of the hole which led to a sticky brake
user_deleted
Well-known member
i would NOT ride this thing until problem solved. you need to attend to both the caliper and the master cylinder. in essence the pads are generating heat, the heat and fluid pressure is pressing the pads against the rotor....they won't retract because the piston bores are corroded and/or the master cylinder is internally corroded and bleed-off return hole clogged. if you're not comfortable removing and checking both the m/cyl and caliper then have a pro do it. these 2 items are intricate pieces, a bit complex, and not for the amateur to work on. sounds as if both need examined and rebuilt and reinstalled with proper system bleed and Dot-4 fluid.
Right now it is released. I can't not ride it. It calls to me "ride me Tony". I just don't use the rear brake. I'll take it apart this weekend. What is the bleed hole return? Sounds like that would be the issue. I know the problem is in the master cylinder. Just not sure what's wrong with it yet.
go cytocis
Well-known member
- Joined
- May 28, 2012
- Messages
- 1,784
You have poor braking technique & even poorer judgement. As lunatic says, I'd stay off the bike until you've got the brake fixed. I'd also recommend a refresher rider training course to get you reacquainted with how to brake. That rear brake is pretty essential in emergencies...
user_deleted
Well-known member
arikam: GO is one of the most knowledgeable people on this board. i concur with his opinion. riding without a rear brake is inherently dangerous. i'll reiterate: have the entire brake system gone thru. if you don't have front brake problems now you will shortly. your caliper piston is stuck in its bore from either corrosion, air, or master cyl. problem. what i said earlier.
nicholas900
Well-known member
It's just not worth taking chances like that. Just imaging cruising down the highway at 70 and you enter a panic situation. You WILL hit the back brake just from muscle memory and instinct. If it sticks your goose is cooked.
You mention that opening the line will free up the brake. So it would seem the m/c is sticking. Seriously... the rebuild kit is like 20 bucks.
But while your at it why not rebuild the caliper, another 20 bucks or so and put on some new pads?
Be safe bro.
You mention that opening the line will free up the brake. So it would seem the m/c is sticking. Seriously... the rebuild kit is like 20 bucks.
But while your at it why not rebuild the caliper, another 20 bucks or so and put on some new pads?
Be safe bro.
go cytocis
Well-known member
- Joined
- May 28, 2012
- Messages
- 1,784
"Adventure" & "stupidity" are quite different things!
Twin Motorcycles had a nice write up a while back about how to keep the rear plunger assembly clean & lubricated as it is a fairly common problem on the XB's especially if you ride in a hostile environment. Mine started to do the exact same thing until I started giving it attention every time I service the bike. If it is bad, I would follow lunatic's advice and rebuild each component as the heat may have damaged something else.
Raz
Raz
go cytocis
Well-known member
- Joined
- May 28, 2012
- Messages
- 1,784
Or if you have poor braking technique & don't use your rear brake. Use your rear brake each time you brake & the rear brake won't seize...
You usually don't even need a rebuild kit. You can usually take the caliper apart and clean and reuse all the parts. It's pretty simple, I"d just dive in to it. Rebuilt the caliper, and clean the master. It'll be a good learning experience as well.
