Brakes are driving me INSANE!!!!

[dboogie2288]

Hi All, so this year I decided to service the brakes all the way around. It's been 4 years I believe, and I felt like the lever was going in further than it should to stop me. Anyhow, I bought all new EBC HH brake pads, Motul 660 fluid, and away we went. So after I put on the new pads (which I didnt need to change), I went to flush and bleed the fluid (which I didn't need to do either). My lever goes all the way back to the grip, and I get very little resistance, and while fluid is moving through the bleeder while pumping, I am seeing no air.

Ok, so it's a 15 year old motorcycle, so I bought the master cylinder rebuild kit. Got that in and did the rebuild. The bore looks great, and all the pieces were in good condition I would say. Overall, I felt like it didnt appear necessary, but I was running out of ideas.

I watched a pair of videos regarding the master cylinder rebuild, and its all straight forward. The guy in the video was rebuilding an MC that was caked in gunk, clearly had been leaking, and REALLY needed service. At this time, I have no leaks, no drips, no problems that I can identify. I have stainless lines that are in good condition, and I really would like to ride the connie, but brakes are kind of important. I've done this service before several times, so I just cannot figure that it's something I am doing wrong.

[George R. Young]

This has worked for me, even starting from empty, new lines.

Position the bars so the master cylinder is at the highest point.

Make sure the two little holes in the bottom of the MC are clear (sounds like yours are, but if not, toothpick)

Gently squeeze the brake lever and you should see bubbles rise out of the little holes. Release and repeat until your hand gets tired, tapping the vertical brake line(s) may cause said bubbles to rise faster.

In dire cases, crack the MC banjo fittings and squeeze out any air trapped there.

[dboogie2288]

This has worked for me, even starting from empty, new lines.

Position the bars so the master cylinder is at the highest point.

Make sure the two little holes in the bottom of the MC are clear (sounds like yours are, but if not, toothpick)

Gently squeeze the brake lever and you should see bubbles rise out of the little holes. Release and repeat until your hand gets tired, tapping the vertical brake line(s) may cause said bubbles to rise faster.

In dire cases, crack the MC banjo fittings and squeeze out any air trapped there.

I'll try tapping, but everything you said is on par with what I've done. The MC is clean, I flush the fluid every few years (as I am here), so it doesnt get crazy gross or anything. I'm also going to grab a pack of crush washers, and replace all of them on the lines/banjo bolts. Again, no leaks, but I'm trying everything.

[Daytona_Mike]

Glad to hear you have SS lines.. those are  important if you want good brakes..
Are you able to build any pressure at all?  One trick many of us use to get rid of tiny bubbles in the system is to build pressure then wrap the brake lever tight over night... 

[m in sc]

take the master off. put it in a soft jaw vice. aim it threaded line hole up. fill the threaded banjo fitting vole to prime it. pull master lever back and forth a few times to get it in there. hold finger over hole put back on bike and thread line in. dont pull lever. refill master cyl. put lid on & tighten banjo fitting. pull lever back to bars, zip tie to grip over night as suggested above. tomorrow bleed brakes.

[jacksdad]

Hi. I've built many bikes over the years (I'm 58) and have had this problem many times.
I've also had issues after fitting braided steel lines, and think the problem is very simple! When you drain the entire brake system, tiny air bubbles stay in the lines, and just will not come out. As you have experienced, no matter what you try, the brake remains spongy.
What I've always done is to bleed the brake as best you can, shaking and knocking the new lines will help remove air...but you just cannot expel it completely!
The very simple solution is to pump the lever a few times, then bind the lever so that the brake is locked 'on'. Leave it overnight, this will force the now compressed air bubbles to let go and rise to the top of the system...sounds a bit odd, but it works.
I don't claim to have any real reasons why, but this works every time, so who cares!

[m in sc]

absolutely, that does work really well, but it HAS to have SOME pressure. (hence my suggestion) what it does is, aerated fluid will eventually gather all the airbubbles together under any amount of pressure, and then will rise to the top of any system. with the lever in it allows this to happen by itself and 'burp' out.   

[jacksdad]

I should have also said:
Once you have held the brake under compression for the night, you can try applying very light pressure to the brake lever, just operating the brake a tiny amount, in an on/off motion, whilst also tapping the upper brake lines. As above, you are trying to 'burp' out the last few trapped air bubbles.
If you look into the fluid resovoir, as you gently rock the lever in/out, you should see tiny bubbles come out of the cylinder at the bottom and rise up.
It takes a little practice but once yo get the hang of things, its really very easy 

[dboogie2288]

Arrrrg no change yet. Throwing some more parts at it. Going to replace all the crush washers, and I bought the speed bleeders set. So, we'll see if that helps. I know, I know, should properly identify the problem before buying parts, but it was like 30 bucks over at murphs. If that doesnt work, I'm going to lose it. I should also note, that I do have the SS lines, in the 2 line configuration for the front. So, the crossover is gone. No one mentioned it, but I knew that was a PITA before that I had resolved with the new lines.

I have;
rebuild the master cylinder
pumped the handle a billion times slowly, fast, super slow, every which way and I am not getting any more bubbles
i've bled it, no air at the bottom.
i tied the lever in at the grip for days on end
i've tapped the line while pumping, and not pumping, no change

I've done this maintenance before as I said...several times. I've rebuilt calipers before, and never had this level of BS...so I'm at a loss. If the replacement crush washers and bleeders dont help, then I'm taking it somewhere.

I did ride it around the neighborhood, sans brakes and all, and I miss the connie so much. Been riding the PC a lot lately, and that just isn't the same experience.

[m in sc]

take the master off and prime it like i suggested.

[dboogie2288]

The insanity continues!!

take the master off and prime it like i suggested.

I did that yesterday, and I gave it a little time to settle while putting on the new crush washers and bleeders. It did drop a bit, topped it off and hooked the lines back up. Tied in the lever for 24 hours, and now I have less than I had when I started. This weekend I put on all new crush washers, verified the speigler instructions to ensure my 2 line system was installed per spec, and it was, and installed the speed bleeders. I still have no leaks anywhere and zero resistance. Not even enough pressure to push fluid through the speed bleeders.

When I did the master rebuild, I did take it apart again and verify that the seal didnt roll. In addition, the new piston comes with the seals preinstalled so I couldn't goof em up reversing them. I'm really getting cheesed on this one.

[dboogie2288]

Vacuum bleeder will be here tomorrow. Hopefully that is the cure for all my issues.