All,

Wanted to ask you guys about an issue that has been plaguing me for about two years now. Sorry in advance for the length...

Background info: I am the only owner of a 2005 636 Ninja with about 15k miles on it. From date of purchase in Apr. 2005 until about Nov. 2007 I rode this bike nearly every day (probably never sat for more than 5 days tops) while living in sunny FL. By the winter of 2007 I had moved to MD and stored the bike in my garage. I really was ignorant about "winterizing" the bike so it just sat there. In Mar. 2008 I was ready to ride again but found the battery was dead and the front brakes were dead too, no pressure or stopping ability at all. Had it towed to a local shop where they got back to riding condition. Note: While I consider myself a fairly experienced rider I am neither knowledgeable or confident enough for mechanical work (esp. on the bike). Anyway, things were fine for about two weeks when one day I was leaving work when I noticed the brakes were noticeably mushy and I really had to squeeze to get the stopping feel I was used to. Took the bike back to the shop and they said probably some air in the line and they would bleed them again. Things were fine again for another 10 tens or so before same thing occurred. After another trip to the shop they said my master cylinder needed to be replaced. I bought the part but had it installed at another shop along with new brake pads.

Current Status: If the bike sits for more than a few days it loses all pressure again and again. I've been away from home for work for about a year now and a good friend stores the bike for me (in FL). He unlike me is very mechanically able and he bleeds the brakes frequently and rides the bike at least once every two weeks to keep everything running. He advised me to post on some forums to ask questions and see if anyone else has seen these issues before. What do you guys think? I love this bike except for these brake problems. No leak can't be found in the line and the reservoir seems to stay full. Any help would be greatly appreciated!

Steven

 

hmm, a new Master cylinder and pads with frequent bleedings, so your fluid is fresh. No signs of leaks from the banjo's because of the fluid level. Next question is of the reservoir bladder and cap along with porous lines. I would probably change out the lines to stainless and get it over with, ride it and see how that goes first. Just a thought. Unless your new mc is faulty for whatever reason. Good luck

Welcome to KF

 

My first though was moisture in the brake fluid, but that would have been changed with the master cylinder. Unless your friend is doing something wrong when he's bleeding them, I'd be thinking the new m/c. It may be that regular bleeding (and topping up) is masking a slight leak from one of the caliper pistons.

Rob

 

I think you may be onto something, Drag^. The rubber "gasket" thingy which goes under the reservoir cap may have a crack in it. The smallest crack can let air out; especially under pressure when you squeeze the lever. Have you thoroughly inspected your calipers? If you've replaced the M/C, that leaves the lines, junction, or calipers. Double check the bleed screws to make sure they're seating.
Keep us posted, and welcome to the forums!