Front brake question 98 kx250

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argclh6670
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Front brake question 98 kx250

Post by argclh6670 »

Hey guys...in a race couple weeks ago my sons front caliper locked up out on course, luckily it was close to tools and i was able to pull the system to allow him to finish...got it home and rebuilt both with new pads. Inspected everything also...for some dang reason i couldnt get it to build any pressure....was even using a vacuum bleeder tool. Any suggestions why? Im drawing a blank... I eventually robbed the front brake system off of out 250 kx hybrid bleed down and built pressure normal.
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bufftester
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Re: Front brake question 98 kx250

Post by bufftester »

Sounds like the master cylinder relief isn't working correctly, they're fairly easy to rebuild, kits aren't that expensive, like 15-20$
argclh6670
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Re: Front brake question 98 kx250

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bufftester wrote:Sounds like the master cylinder relief isn't working correctly, they're fairly easy to rebuild, kits aren't that expensive, like 15-20$
Hey Buffster, hows the RMX treating you? Still have it? As far as rebuilding....I've done that. but, still nothing thats why im drawing a blank...
david
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Re: Front brake question 98 kx250

Post by david »

Are you sure you put the piston cup on the correct direction?
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Tyl3r
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Re: Front brake question 98 kx250

Post by Tyl3r »

I feel like most of the time I can't get the brakes to build pressure, its usually fixed with a quick master cylinder bleed after I've tried everything else. Just pump up the brake a few times, hold the lever, crack the banjo bolt real quick, and snug it back up. Might be worth a try if nothing else is doing it :hmm:
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John_S
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Re: Front brake question 98 kx250

Post by John_S »

I had one that was tough to build up pressure and read up on reverse bleeding. I must've pumped it and cracked the bolt 50 times it seemed and couldn't get anything more than a 1/2 way decent feel. I bought a reverse bleeder kit off eBay for about $15 and it worked right away with a great pedal feel. I'll reverse bleed from here on out.
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Tyl3r
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Re: Front brake question 98 kx250

Post by Tyl3r »

I got one of those too and I feel like its hit or miss. Worked great on my rear brakes on my hybrid and dual sport, used it on both ends of my buddy's KTM and it was perfect, but it won't do my the front lines on my hybrid. I couldn't get it to push the fluid in. I don't know if its my bleeder or what (the vacuum bleeder ended up working out with a rebuilt master cyl)? I do agree tho, it is great, especially with new lines, as long as you can get the fluid to go in haha.
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bufftester
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Re: Front brake question 98 kx250

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argclh6670 wrote:
bufftester wrote:Sounds like the master cylinder relief isn't working correctly, they're fairly easy to rebuild, kits aren't that expensive, like 15-20$
Hey Buffster, hows the RMX treating you? Still have it? As far as rebuilding....I've done that. but, still nothing thats why im drawing a blank...
Still have it, it's running much better since I dumped the crappy PJ carb and went to a PWK. Outruns the KDX for sure! As for the bleeding issues, I haven't really had any problems with mine so not much help there, although I have always used my mighty-vac to pull fluid down so maybe that's why. It helps to try and get rid of any high points in the brake line where it sits above the master cylinder, as those are where the air bubbles sit generally.
argclh6670
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Re: Front brake question 98 kx250

Post by argclh6670 »

Thank you all for the suggestions!! I finally got the brakes to build pressure after the rebuilding master cyl and caliper.....however, my son went riding today and they siezed up again just as before....what would cause this? Would u guys lean more towards the master cyl or caliper being the issue
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bufftester
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Re: Front brake question 98 kx250

Post by bufftester »

If it's working fine and then locks up as you go, something is wrong with the master cylinder. I see you rebuilt it, so maybe there is some other issue with it. Check the reservoir and make sure that the return/fill holes are clear
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