xj550 Master Cylinder rebuild -- not so good

Hey y'all!
I am giving up for the night, and looking for suggestions where to start tomorrow.

Initial symptoms:
Major geyser inside reservoir
brake lever got firm, but pulled all the way to the grip.
Braking power seemed good at 30 MPH or so

The bore was nice and shiny -- no scratches at all
clean, clean, clean
The kit went in like a charm
Bench bled the MC with my new mity-vac (thaks chacal!) -- I was amazed how much air came out. Took 20 minutes. After wiping up the mess from hooking up the fill cup backwards. filled the cup about 2/3 full.
[edit] installed the MC on the bike and attached the brake line.
Bled the brakes from the bleeder valve. Amazingly slow. I pumped the handle a lot to speed the process. Got a number of major air bubbles out, then nothing. Couldn't even tell the fluid was moving unless I pumped the handle. Filled 1/2 the bottle or so.

Current symptoms:
no geyser!
no resistance to the brake lever at all -- cush'es all the way in.

Tomorrow I plan to bench bleed again.

Suggestions?

 

My first suggestion would be to assemble it all onto the bike and then bleed.

 

bigfitz -- sorry I wasn't clear. After the bench bleed I replaced the MC onto the bike, refit the brake line, and bled the whole thing from the caliper bleeder valve.
Thanks!

 

Could it be an issue at the caliper now and not the M/C? I had a corroded bleed screw that would NOT "close off" fully (even though it seemed tight) I ended up replacing it.

 

bigfitz52 -- you are a friggin genius! The bleeder valve was crushed and would only draw out air, not brake fluid, so once it got the air out from around the valve it stopped bleeding. The pressure from working the lever forced fluid through the tiny gap, but not enough to properly bleed. The collapsed vacuum hose should have been a clue!

Now -- the brakes are tremendously better than before but still spongy. I can lock up the front tire at parking lot speeds -- there was light rain today so I will check it out again when it's dry. Another issue is "diving" if I am using the correct term. The front shocks seem to compress all the way even at a low speed stop. Well, that's another project. Once I get the shocks dialed in I will see how good the braking is in real life.

 

The stock front forks ARE a bit wimpy; you can get an upgrade from Progressive in the form of new fork springs for about $75. Worth every penny.

 

I know this is hindsight, but I like to check my bleed valves before taking things apart. Always easier to ride out to get parts when you still have brakes.
Most bleed valves are simple in design, just drill holes, and no actual valves in the unit. I have resurrected several bleed valves with a small drill bit, guitar string, and some carb cleaner/brake fluid. Bleed valves are cheap too, just make sure you take one to the store when getting a new one.

 

richt -- thanks. I considered drilling the bleed valve out, but it was pretty well crushed, so I drove around (raining!) for an hour and found one.

bigfitz52 -- thanks for the heads-up on the springs. I will consider preloading the springs (or chopping and preloading) later. For now I checked the oil and one was dry. Sigh

Did I mention I broke the MC bracket that clamps onto the handlebar *and* the right hand mirror trying to free up the mounting bolt in my vise? What would we do without chacal and priority shipping?

Damn! I am just trying to get the bike safe so my sweetie can decide if she likes it. If she does I will start the upgrades and serious tinkerage. If not, well I *might* still keep it *wink*.