brake question

[jjz28]

Hey guys just wondering if anyone has had this problem and what the fix was. if I use my rear brakes they will slowly start to apply by themselves slowly going down the road so I have to stop and "pop" the line to make them come loose and if I don't use them I wont have to stop again unless I use them. They don't lock up when I use them, its just after I use them a ways down the road the will slowly get tight and start smoking until I stop and pop the line open. I tried bleeding them. I have never took the caliper apart and cleaned it but I think I will try that today since it will be raining. Also it seems like my brakes don't really work great. They stop me but it just seems they could be much better. Maybe if I got stainless lines it would be better than the old rubber ones. This is only me second season so I am not really experienced on bikes yet. I know the engine stuff pretty good just not the brakes or how good they are supposed to be. Thanks guys.

[jayel]

master cylinder needs cleaned, it's not allowing fluid to bleed back

[jayel]

can't find a pic but there are two holes in the MC's fluid cup that allow fluid to get to the MC piston, one is smaller, it is the bleed back hole very easy to plug up if fluid is old and dirty

[jjz28]

Thanks buddy, I am going to take it off and clean it again. I did clean it a long time ago but I must have not got it good enough. I cant figure out how to get the back caliper off either.

[natemoen]

Yup, need to clean the spooge hole. It is a very small hole that lets the line pressure return back to normal.

[bikerphil]

I cant figure out how to get the back caliper off either.

There is a hidden screw, you can access it from the left side thru the wheel spokes at 12 o'clock position.

[jetmechmarty]

the spooge hole



The above images will show you the passage that is clogged in you master cylinder. It's the little one.

If you can't clear it with solvent, a guitar string is often recommended.

[DGXSER]

It took me a while to find that little phillips screw in the back of the caliper as well.

To clean the spooge hole in the rear MC, you need to pull that bolt out the side of the MC, I use a wire out of a wire brush to clean those little holes out.

[jjz28]

yeah, I finally found the screw from an older post on here. The holes were clear but I took a needle through them again but the piston and caliper was nasty. The rubber looked good so I took everything apart and the piston out and the rubber ring and cleaned it up real good but now I am having trouble getting them to bleed now. I think last time I let it sit overnight and it bled the rest of the way. Thanks guys. Oh, last time I used a syringe on the front to push the fluid through but not the rear.

[jjz28]

I cant get the bleeder valve open. I tried bleeding through the banjo bolt and got lots of air but its seems to be going nowhere. I need to get the bleeder out (its rounded off) any suggestions? I could push the fluid in backwards if I got it off.

[fredintoon]

I cant get the bleeder valve open. I tried bleeding through the banjo bolt and got lots of air but its seems to be going nowhere. I need to get the bleeder out (its rounded off) any suggestions? I could push the fluid in backwards if I got it off.

Hi Jeff,
if a 6-point deep socket don't work, try filing the flats to the next size down and if that can't be done in situ, use a visegrip.
Once the bleeder is out, toss it and get a new one.
If the Yamaha bleeder is hard to find there's a GM one that's a tad longer but fits OK.
Or try Speedbleeders, never used them but others say they work as claimed.
DON'T reef the new bleeder up too tight. My son reefed hard enough on his to partially collapse it's nose cone so it couldn't fully seal.

[Axel]

self bleed

block the pedal so it has constant pressure - leave overnight

[jjz28]

I tried the vise grips (it is completely rounded at this stage) and the metal is just too soft it just twists off pieces rounding it more. I used heat too. I will try blocking the pedal down.

[jjz28]

I have some of those sockets for rounded bolts but I don't have a small enough one. I'll have to find something to get it out. If I can push the fluid in through the bleeder, it will work much better.

[bikerphil]

If you can't get the bleeder screw out, I would just get another caliper. They are a pretty common part, you could even use a right front from a Standard on the rear if need be.