Welcome guest, is this your first visit? Create Account now to join.

Welcome to the Motorcycle Forum.

Register ButtonIf this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed.

+ Reply to Thread
Results 1 to 3 of 3
  1. #1
    Where Am I ?
    My Bike(s)
    '85 Nighthawk, '80 Yamaha 1100 Special
    Location
    MN
    Posts
    38

    XS1100 rear brakes

    I have a 1980 XS1100SG and am having a problem with the rear brake. Sometimes I'll be sitting at a light with my foot on the rear brake and all of a sudden the pedal will lose pressure and sink all the way down. If I let go and push it again, all is ok....for a while then the same thing will happen.

    I've bled the rear brakes multiple times, still does the same thing. Still seems to be losing pressure. I'm no mechanic but if there is a leak in the system allowing air to get it wouldn't the brake fluid be leaking out the same place? I see no evidence of brake fluid leaking at all.

    Thanks to all.

  2. MotorcycleForums.net is the original Motorcycle Forum! Registered Users do not see these ads. Please Register - It's Free!

  3. #2
    M-J Master Poster
    My Bike(s)
    Vulcan 2000
    Location
    North Alabama
    Posts
    3,829
    Quote Originally Posted by wapam View Post
    I have a 1980 XS1100SG and am having a problem with the rear brake. Sometimes I'll be sitting at a light with my foot on the rear brake and all of a sudden the pedal will lose pressure and sink all the way down. If I let go and push it again, all is ok....for a while then the same thing will happen.

    I've bled the rear brakes multiple times, still does the same thing. Still seems to be losing pressure. I'm no mechanic but if there is a leak in the system allowing air to get it wouldn't the brake fluid be leaking out the same place? I see no evidence of brake fluid leaking at all.

    Thanks to all.
    That's a great bike you got there. I used to run a highly modified '79 XS1100 Special through Deal's Gap a lot. Tons and tons of power. They called that bike Special for a reason. I miss that bike.

    I does seem like you would be getting fluid leakage. When the pedal goes down, you're moving something, be it air or fluid.

    I'm wondering if the caliper pistons are freezing up and sometimes sustained pressure releases them or maybe there's an aneurysm in the line (a weak part that bubbles out under pressure) that you can't see when you are sitting on the bike with the brake pressed or when you're off of the bike, looking directly at it with minimal or no pressure on the brake. Your hand certainly can't apply sufficient pressure on the brake like your foot can. Can you duplicate it when the engine/brakes are cold?

    Hmmm... that's a tuffy.
    Last edited by diamond_jim; 05-07-2008 at 03:42 PM.

  4. #3
    M-J Lifetime Achievement Award
    My Bike(s)
    '10 Kaw Vulcan 900 Custom
    Location
    Ocala, FL
    Posts
    8,539
    Quote Originally Posted by wapam View Post
    I'm no mechanic but if there is a leak in the system allowing air to get it wouldn't the brake fluid be leaking out the same place? I see no evidence of brake fluid leaking at all.
    Master cylinder failure. The fluid is leaking past the piston.

    It may have a secondary seal so that you get some resistance (and some braking) very near the end of the throw.
    Don't believe everything that you think.


 

Ads

 

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Similar Threads

  1. Rear Brakes?
    By Redd2ride in forum Bandit Lair
    Replies: 3
    Last Post: 04-01-2008, 09:22 AM
  2. rear brakes
    By thurst2k in forum Gixxer Mixer
    Replies: 10
    Last Post: 09-04-2007, 03:02 PM
  3. Replaced Rear Brakes
    By jmet77 in forum Katana Planet Emergency Shelter
    Replies: 7
    Last Post: 06-04-2007, 08:33 PM
  4. Rear brakes
    By 03gsxr600 in forum Sportbikes & Sport-tourers
    Replies: 5
    Last Post: 09-21-2005, 07:54 AM
  5. Nobody needs rear brakes!
    By tlwisner in forum Tips & Training
    Replies: 21
    Last Post: 10-11-2004, 09:14 AM

Search tags for this page

1980 yamaha xs 1100 brakes

,

bleeding brakes on 70 yamaha xs 1100 special

,
brake pedal sticking on 1980 yamaha xs1100
,
rear brake stiff on 1980 yamaha xs1100
,

rear master cylinder for 1980 yamaha xs1100

,

xs1100 brake bleeding

,

xs1100 rear brake

,

xs1100 rear brake bleeding

,

xs1100 rear master cylinder

,
yamaha xs1100 rear break
Click on a term to search for related topics.