master cylinder bubbling problem bleeding brakes
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master cylinder bubbling problem bleeding brakes
Okay so I have been doing a bunch of work on my 06 night train and when i was all done i took it for a spin but the brakes didn't feel right. They had very little stopping power. so i opened the cylinders and found out they were low on fluid. I went and rented a vacuum pump from advanced auto parts and tried the following:
1. remove lid of master cylinder
2. attach hose to pump and nipple on caliper
3. pump to 10 hg
4. open valve on caliper
It seemed to pump most of the fluid out and i think I might have got some air in the lines.
The strange thing is that the whole time i was pumping and draining the fluid, the master cylinder was bubbling and spilling out fluid. This didnt seem to add up. Any ideas why this will happen?
I tried to add more fluid and pump it through but now I can't get any pressure on the hand lever and the pump doesn't seem to pull any through. it just bubbles. Did I damage something in the master cylinder? Thanks in advance.
1. remove lid of master cylinder
2. attach hose to pump and nipple on caliper
3. pump to 10 hg
4. open valve on caliper
It seemed to pump most of the fluid out and i think I might have got some air in the lines.
The strange thing is that the whole time i was pumping and draining the fluid, the master cylinder was bubbling and spilling out fluid. This didnt seem to add up. Any ideas why this will happen?
I tried to add more fluid and pump it through but now I can't get any pressure on the hand lever and the pump doesn't seem to pull any through. it just bubbles. Did I damage something in the master cylinder? Thanks in advance.
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Joined: Aug 2009
Posts: 2,729
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From: Republic of Texas
Years ago I had one hellavu time getting all of the air out of the system. I had gotten them to where I had brakes but they still felt spongy. So what I did was top off the rear reservoir and placed the lids back on them but did not tighten the lid down. I unbolted the rear caliper and laid it on the floor so that the caliper was lower than the reservoir. On the front I topped off the reservoir and placed the lid back on leaving the lid loose and turned the handle bars to the left. Turning the bars to the left helps maintain vertical path for the air bubbles to follow all the way back into the reservoir. Same holds true for the removing the rear caliper and placing it below the reservoir. I let the bike sit overnight. Came out the next morning and the brakes were perfect.
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Joined: Jul 2011
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From: Boston, MA
Years ago I had one hellavu time getting all of the air out of the system. I had gotten them to where I had brakes but they still felt spongy. So what I did was top off the rear reservoir and placed the lids back on them but did not tighten the lid down. I unbolted the rear caliper and laid it on the floor so that the caliper was lower than the reservoir. On the front I topped off the reservoir and placed the lid back on leaving the lid loose and turned the handle bars to the left. Turning the bars to the left helps maintain vertical path for the air bubbles to follow all the way back into the reservoir. Same holds true for the removing the rear caliper and placing it below the reservoir. I let the bike sit overnight. Came out the next morning and the brakes were perfect.
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That is what I thought. Now I have sure in the lines from letting the mc get too low. I pump the brake lever and no resistance builds. Any suggestions?
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