Frustrating Front Brake

[Will McD]

1982 CB650. I broke my old brake reservoir during a spill so I replaced it with an identical new one. I installed it and then bled the brakes. My first time. After bleeding it the first time I put the cap back on and pumped the brake lever a few times expecting pressure to build up or something... nothing happened.

I tried bleeding the brakes with a length of hose suspended above the caliper and full of fluid. When I pull the lever in the fluid level rises (along with a few bubbles at first) and when i let it out it sucks some fluid back in. That seemed right to me, so i did that until no more bubbles. (tapping on the lines to unstuck the stuck ones). I close the needle, put the cap back on and still no pressure

Almost no resistance at all.

I know fluid is going from the reservoir to the lines because the level in the reservoir dropped. I know the brakes worked before I took the spill, so it shouldn't be a bad seal right? Where should I start looking? I dont want to tear apart everything and try bleeding again if I am doing something wrong to begin with. I would expect if there is a small leak it would still be possible to get some pressure by rapidly pumping the brakes, but I can't. Also, the pads are not stuck on, the wheel turns freely. (I tried the search but nothing helpful could be found) Thanks for any help! The nice weather is killing me with my bike stuck in the garage.

 

[forcefanajd]

do you have access to a mighty vac? they are like $20 from autozone and very handy to have anyways, to me it sounds like you have air in the master.

 

[hillsy]

You have air in the system.

Mity vac or a $1 syringe and a small length of hose.

The Mity vac is easier for most people to use, the syringe takes a bit of practice.

But the syringe allows you to push fluid into the caliper through the bleed nipple and UP the lines so you're not fighting gravity. Sometimes that's the only way.

 

[Tim]

Speed Bleeder - Google it.

I use one on my BMW. Open the bleeder, hose into a jar. Then up top I just keep pumping and adding fluid to the MC until nothing but nice fresh fluid is coming out the bottom with no bubbles. I run through a good bottle+ when I do it, which is about two times in the last 5 years. I like to flush it out really well.

 

[Will McD]

Hmm yah. The more I read up on manual brake bleeding the more I hear it is really difficult, so i doubt I got it right my first or second try. I will buy a mityvac and give it a go. Thanks guys, much appreciated. I posted over in sohc4 2 days ago with no responses, and I get 2 responses almost immediately here
Ill update if it works.

edit- 3 responses

 

[forcefanajd]

+1 on speed bleeders, i use them on my bike too, if you want them for your bike go to your local napa store with your old bleeder in hand and they should have them in stock. the part number is: BK6751572 and they are $10.80 plus tax for a pair.

 

[rockcitycafe]

sounds like your master cylinder replacement could be shot, it's the only thing you've changed... was it brand new? or on ebay, listed as "working"