brakes...no pressure, overnight ...viola

[chud271]

I have a 80 gs750e. It has been in pieces in my garage for the past 7 years or so. So I have been going through the entire bike and when I got around to the front brakes, I had all sorts of trouble bleeding them. I found a post here the other night, but for the life of me I can't find it again.

Here's my question. I completely disassembled the calipers. Dust boot, piston, the works.. and cleaned them thoroughly with new brake fluid. (as clymer says to do) All is fine, and I put the calipers back together and begin to bleed the system. I had back filled the caliper to alleviate some of the air in the system. I started bleeding the brakes, furthest side first, and after a few minutes on both sides, I had clear fluid with no bubbles or contaminates. The strange thing is.. I had no resistance on the lever. So, I continued to bleed another HALF of a bottle of brake fluid through the system on both sides, thinking there was still air in it. 35 minutes later.. still nothing. I got *@%^$*@%^$*@%^$*@%^$ed off and left it for the night.

So I check the bike this morning and I have got enough front brakes for everyone in the forum!!! Did the mystery mechanic sneak into my garage and do it for me? This is my question... WHAT the hell happened overnight to make the handle have resistance????@!@@@

My brakes are working fine now.. Could someone please explain? Thanks for all the tips on this site.

[Jeff Tate]

I'm not for sure why that happened, but don't ya just love problems that fix themselves?

[Anonymous]

Did the fluid level in the master cylinder go down over night too? I've noticed that the master cylinders take for ever to bleed. It takes me 20 minutes of repeatedly pumping the lever before my brakes even begin to work after cleaning them out as they get air locks and don't have enough suction to prime themselves properly.

Steve

[chud271]

Did the fluid level in the master cylinder go down over night too? I've noticed that the master cylinders take for ever to bleed. It takes me 20 minutes of repeatedly pumping the lever before my brakes even begin to work after cleaning them out as they get air locks and don't have enough suction to prime themselves properly.

Steve

actually, the fluid level is fine. That's what blew my mind. If it had gone down, I would have thought that the air had surfaced in the resevoir.. but it is still full..

I read your posts earlier. Sounds like you had some fun with your bike as well.

[focus frenzy]

easy!! the check valve was stuck open, it free'd up sitting overnight in the fresh fluid and closed!!
normaly they will stick closed and when alittle heat builds up in the fluid they will make the brakes stick and drag, as the heat builds from the dragging they bind even harder, this is what I had, and often see others have happen, I have seen this happen plenty of times on cars, go for the brakes and the pedal hits the floor, let off and try again and presto, the brakes are back.

the purpose for the check valve is to alow fluid to pass to the caliper to make up for pad wear, and to alow expanding fluid to return to the reservoir.