Hi all!

Need some feedback from you experts...I replaced brake fluid in master cylinder and did bleed both Lt and Rt side calipers (used a vacuum brake bleeding system) after topping off reservoir and tightening everything up it seemed that the front wheel will only spin barely one revolution. Tried to reblled the system to purge any air trapped in the lines etc...and still same sticky problem with spin???

Appreciate all the feedback!

Thanks!
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FILOLI - Fight, Love, Live

Over filled resevoir?
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If I have to take the carbs off once more...

You may have a sticking caliper. Can you isolate it to one rotor or the other? are any of the lines kinked?
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james
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how well does the wheel spin without the calipers on? Possible the front wheel is out of alignment and being "crooked' in the forks is binding it against the calipers.

The best way I found to set the front forks is to determine one fork leg (I like to use the side that the axle goes through first) and tighten it down in the top and lower triple (setting the height you want). Keep the other fork loose in the triples. Put the front wheel into place and push the axle through. Adjust the loose fork leg's placement in the triples so the axle slides smoothly in and out. Once you get that, tighten down the loose fork leg, and you should be good for the forks being even in the triple and the front wheel will spin freely.

If the brakes are still binding, then your pistons could be stuck and you need to check those.
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Charles Gallant

Hi all, will be able to get back into the garage this eve and recheck everything.

Brake fluid is in the middle of Low/high marks in the reservoir, Caliper sticking? I don't know if it is. The wheel spins perfectly and for at least 12-15 seconds with a good spin without the calipers on the rotors. Which indicate that the forks and wheel are aligned properly. I have never pulled the fork tubes out of the triples since owning the mc21. This leads me to believe that it is probably time to do the very thing I have avoided for years...Rebuild a caliper.

So, my questions now move to - can anyone give me some good tips to rebuilding the nissin 4pot calipers (stock mc21r), as far as removing lines, banjo bolts, the 4 star/cross pattern bolts that need to be removed to separate caliper. When removing the pistons themselves are there any particular things I should be aware of? Should I replace all the piston seals or just give them a good cleaning w/brakecleener and reassemble. Probably have to assses after taken out though I imagine.

Thanks all!
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FILOLI - Fight, Love, Live

when rebuilding, replace ALL seals. Your wasting your time if you don't

With the calipers still bolted together, drain all the fluids you can from it. Then used compressed air to help push the pistons out. Clean the pistons really good so there is no gunk left on them. clean up the caliper bodies really well, paying attention to where the pistons go.

Don't use marring tool on the pistons when trying to remove them.

As for the alignment of the front wheel, just cause the wheel spins freely without the calipers doesn't mean the forks are straight. Make sure that axle slides into the forks/wheel without binding, and withouth the use of a mallot, or other tool to drive it in. Honeslty, that axel should just slide right in with no issues.

You may also want to check the master cylinder to make sure it's working properly. It's a two way valve basically. Pull the lever and it pushes fluid into the lines. Let the lever off, and it releases pressure in the lines. if it's not working on the release part then your calipers could bind on the discs.
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Charles Gallant