KZ1000A1 twin front brake bleeding

My KZ1000A1 has the twin front brake setup. The splitter was fitted reversed when I got the bike but the brakes were working OK. Today I have re-fitted it the right way round but try as I might I can't get the air out. Garage floor is covered in brake fluid! I have fitted and bled brakes many times but this is beating me...

PS: all unions fitted with new copper washers, no leaks anywhere else

Some folks have had luck bleeding the front brakes by pulling the brake lever in and taping or tying it in that position overnight. From what I've read that permits the air bubbles to gradually rise out of the brake lines. If nothing else works, it's worth a try. Ed

Thanks for the tip, I now remember being told that trick in the past. I'll give it a try,

Tying back the brake lever puts the system under constant pressure and allows the caliper pistons to slowly creep closer to the disc. This can improve lever firmness in the cases where the caliper seals are binding against the pistons and not allowing the pistons to slide through the seal like they should. I've seen this occur on two different occasions when K&L brake caliper seals were used. A real pain in the butt. The lever feels like there is air in the system, only there isn't. It's just that the pistons are parking too far away from the disc because the piston seals are binding.

In some special scenarios it will help if you hang up the brake caliper (plus splitter) over the master cylinder
brake fluid level to get the air bubbles out of the brake lines. Put the bleeders on the highest point and a piece
of wood between the brake piston. Bleeding out the bubbles will go easier now.

Michael

There is no lever firmness at all at the moment, despite fluid coming out of both bleeds. All I have done here is disconnect the brake lines and put them back where they should be. The brakes worked fine just before that. There must be a huge air lock somewhere....

My son and I just did my 550 front last night. Installed new m.c. we had no pressure for prob about 5 fill ups of the m.c.

Maybe it's not just me then!

It's definitely not just you. When I rebuilt my KZ650-C1 (dual disk) front MC many years ago I had a heck of a time bleeding all the air out. It took days. Now I use a pressure bleeder that makes changing brake fluid very simple, but I haven't introduced any air into the brake lines or I might have had the same problem again. Ed

If brake fluid came out of the bleeder there will no pressure until you close the bleeder.
Air bubbles don´t like to flow down to the brake caliper with the little amount of brake fluid of every pull
of the master cylinder leveler. Sometimes they flowing back to the M.C when you release the leveler.
You have to close the bleeder to prevent sucking in air into the system before you release the leveler!
that's why i do the brake caliper hang up over the master cylinder brake fluid level trick.
Air bubbles will go up in the brake line and don´t flow back to the M.C.

Michael

If brake fluid came out of the bleeder there will no pressure until you close the bleeder.

I've been doing that all afternoon. I've left it taped up now.

I use tubing on the bleeders laying in a container with fluid in it. That way air can't be sucked back into the system. I still had a problem so I bled at the different banjos starting at the lowest one working up to the MC. Messy but it worked.
Steve