Has anyone replaced their master cylinder? - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 4 (permalink) Old 06-26-2004, 08:37 PM Thread Starter
 
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Question Has anyone replaced their master cylinder?

I recently installed Galfer stainless steel braided brake lines on my '96 VN750. It only has 6,400 miles and I doubt the brake fluid had ever been changed 'till I bought the bike in Nov '02. After installing the new lines and bleeding then tying the brake lever back for a few days to allow the bubbles to escape the lever was nice and firm. Then within 30 mins of riding the lever lost it's firmness. It came back as far as it did before the line change - almost to the rubber grip! The bike does stop, and decently at that but certainly doesn't inspire confidence with the lever acting like that. I bled the brakes and tied the lever off again, and again I had I nice firm lever only to lose it's firmness as before. At this point I suspect the master cylinder has a bad seal and/or corrosion in the piston bore resulting in an internal leak. There are no leaks anywhere. A new master cyl is $197, and a new piston with seals is about $28. Any advice or experiences?

-Bruce
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post #2 of 4 (permalink) Old 06-27-2004, 07:03 PM
 
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Re: Has anyone replaced their master cylinder?

Bruce...before you go and change out the MC, check to be sure you have no leaks @ the banjo bolts on the caliper. Those Galfer lines fr Cyclebrakes are abt 1in too short, IMO. When I installed mine LY, I had a bit of a time getting the banjo to seat perfectly against the crush washers they give you, esp on the left side. I had 'microscopic' leaks @ both banjos till I re-routed the lines. DOT4 was leaking out, and air was leaking in, I'm sure.....
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post #3 of 4 (permalink) Old 06-27-2004, 07:59 PM Thread Starter
 
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Re: Has anyone replaced their master cylinder?

jm1515,

I got my lines from cyclebrakes.com too but they fit perfectly. I spent some time fitting them before I bolted 'em up. I don't seem to have any leaks and everything is torqued to Galfer's recommended 14 ft/lb using a quality torque wrench. I'd really prefer not to have to by a master cylinder but the brake lever came back just as far and felt about as "spongy" when the original rubber lines were on the bike.
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post #4 of 4 (permalink) Old 09-22-2012, 05:41 PM
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I did the fluid-change , and had the same problem with spongy lever after a while. Here is what i did... loosen the calipers and take the bottom screw out , thet way you get the bleeding-screw right on top. I had a airbubble lying in the top of the piston which didnt go out the bleeding-nipple..
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