Can't bleed KZ750 H2 after caliper rebuild?

The reason for seeing air all the time with any suction system attached to a stock bleeder, is that the suction will pull air around the threads of the bleeder nipple. But it will also pull instead of push against seals in your master that were meant as Pressure seals, not vacuum seals.
Make sure that the Fluid return port in the floor of the reservoir is open. There are two holes in the reservoir floor, going into the piston chamber, the on closest tot he outlet banjo is the fluid return port.

the master cylinder i have is the type with the round plastic cup, not the rectangle aluminum one, so i cannot actually see the action on the fluid return hole.

I positively cleaned both ports before putting back together, and i am sure it is open as air did come out of it while i was bench bleeding and let all the rising air out as well.

Right now i am not getting ANY air out at all, with or with out the vacuum pump.

No more Air, but no pressure at all, not even spongy?
Both the front and back brakes are giving problems?
The rear should be pretty easy to bleed. Bleeder closed, push down on pedal, open then close bleeder, than let pedal return fully. Repeat.
The fronts get air trapped due to the Bleeders being at the bottom and the master at the top. There are a lot of different tricks. One I use is to remove both calipers. Wedge a block of wood in between the pads, get the calipers up high in the air, above the master. Then bleed the brake. Keeping the bike on the side stand, with the bars set so the master has the banjo lower than the lever, so any air can come out the fluid return.

"I have just rebuilt all three calipers on my 81 kz750 h2.
New seals and boots, and some new lines."

Why No Kits for the Masters?

krifartida wrote: I did...

Did you get any kind of resistance at lever when you bench bled it?

When filling the brake system with fluid, may use an inexpensive rubber ball style syringe with a short hose attached to the end which connects snugly over the bleeder nipple.

M/C reservoir is uncovered (to watch the fluid rise up inside).
Bleeder nipple is slightly loosened.
Brake hand lever isn't being squeezed.

Suck a load of fresh "unskaken" fluid into the syringe, remove from fluid and press out the air, and re-immerse and re-suck, repeat as needed until the syringe is almost full.

With the tube pointing upward, squeeze slight pressure on the syringe to expel all air (fluid is barely escaping from end of attached hose).
Holding it in this condition (no air in the syringe or hose), attach the hose onto the bleeder nipple.
Squeezing the syringe will now push fluid from the syringe through the hose and into the bleeder nipple.

Don't release squeeze pressure on the syringe while attached to the loosened bleeder nipple.

If more fluid becomes needed in the syringe, tighten the bleeder nipple before relaxing and removing the syringe.
Refill the syringe and resume the filling process as earlier described.

As fluid fills the system, it will eventually appear and rise up inside the master cylinder.

When the M/C becomes filled, tighten the bleeder, without having relaxed pressure on the syringe.
Then remove the syringe and hose.

Normal bleeding procedure should now expel remaining air from the brake system.

Good Fortune!

i was trying to save a buck... i know i know....

Yes there is pressure now, it actually is better then before but the lever easily travels all the way to the bar and is spongy as hell and offers almost no braking power.

If i new a MC rebuild kit will solve this i will get one right now, but i am trying to eliminate all the other options...

I will try the reverse fluid injection (i saw this done once) and advise on results.

Did you get the rear to work correctly?

Yes the rear is working pretty much perfectly and bled easily. !!

KD2222. Wife bought it for me (after a few non-subtle hints) 8 years ago; best Christmas present ever! I use it on my truck, cars, and bike - no problemo.

???

krifartida wrote: ???

Google: kd tools 2222 brake bleeder
Good Fortune!

I have replaced my master with one of the factory kiss ones off ebay .. i have been figting the spongey lever and have almost gave up..