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Discussion Starter #1
Hi,

I was out riding one day and my front brakes got real spongy. When I got back home, I noticed that the fluid was low. So I filled it up and bleed the brakes... No pedal. Then I took apart the master cylinder and noticed that one of the washers that hold back the spring to the lever was bent, which allowed the piston inside the master cylinder to move too far. So I replaced the washer. Bleed the brakes and still nothing.

Next I replaced the rubber inside the master cylinder and set up a mini brake system with a 19" steel line and one caliper. When I bleed the system, I noticed that the piston in the front caliper was only moving about 1/16th of an inch. Is this normal? I do have a dual caliper's so I was able to verify the same behavior on the other one also.

By the way, I bought new steel braided lines.

Any help is appreciated.
 

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Discussion Starter #2 (Edited)
I also can't seem to get the caliper piston to move out far enough to make the pads squeeze together. Unlike a car, where you can pump your pedal until the caliper is almost the whole way out. Something seems wrong here. Do I need to pump, bleed, pump, bleed, etc. , until the caliper moves out far enough to make contact? Seems to me that the caliper is not moving out (other that the 1/16th inch movement back and forth when I pump the lever.) I need the caliper to stick farther out. Help!
 

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sounds to me like there is corrosion around the pistons not letting them move freely. It is not uncommon for brakelines/systems to get moisture builtup therefore corroding the piston in place. I have experienced this in every vehicle, car, *** bike, harley. You gotta get the piston out and clean the corrosion off the piston and the inside of the caliper. Emery cloth and some penetrating oil.
 

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front brakes

Like Crow says. Take apart clean and rebuild your calipers. Sometimes the piston or poston bore is corroded too badly to re-use, but a clean up or mild hone job with re-build kit may help.
 

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Discussion Starter #5
Thanks for the replies. I can be frustrating to miss a month of good riding during a drought! I got it working now (and its been raining all weekend so far).

What happened is the spring was too big for the master cylinder. It did not allow the piston inside the master cylinder to move enough to push the juice! I cut it down some and it works like a charm. Aftermarket parts!?!?
 

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Discussion Starter #7
cruzencoach said:
cp_ru, are you saying that you found the master cylinder repair kit's return spring to be longer than the original spring?
That is exactly what I am saying.
 
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