Brake bleedin' problem sloved!

[Pigford]

Further to my 'Bleedin Brake' item, I would like to pass my experience on, in a hope it could assist someone in the future!
Although my brakes are not standard Kawasaki Zed, being GSXR 4-pots, this may help one of you?
I had difficulty bleeding my front brake system. Try as I might the only way to get the brakes to work was to rapidly pump 'em & then they felt spongy. I tried many times, over several nights to no avail
I even tried using a big syringe and pump fluid thru' the bleed nipple with no success!
Finally, 1/2 hour ago, I noticed that as I applied the brakes, the left hand disc was flexing! The caliper was not lined up correctly and had a couple of washers behind it. This flexing of the disc meant that the lever piston stroke was not enough to take up the flex & apply full pressure to the pads! This was the spongy feeling (disc flex). I've now disconnected the l/h caliper & with only the r/h connected the brakes feel soopa doopa
I will either shim the l/h caliper or may just run with 1 x disc, as the brakes were too good before, anyway!

[Rich]

Oh Dear !

[chrisu]

I'd shim it properly and have both discs working.

you never know when you might need it........................

[kiwiz]

Got a similar problem with the calipers on front of my J.

A lot of lever application seems to go on movement of the caliper before it bites on the disc. It seems that the caliper is retracting too much as thought there is something which is pulling it back too far when pressure is released. It may be something to do with the caliper sliders, but can't figure out what. The slider pins seem to have a plastic sleeve over part of them. Could this cause this effect?

[Pigford]

Kiwiz, if my experience is anything to go by, sumink must be pushing em too far apart, so there aint enough throw in the level (master cylinder) to recover & apply the brakes
Mine are A1 OK now. Gave 'em a good try to the ACE & back today (270mls)

[Rich]

Kiwiz, if my experience is anything to go by, sumink must be pushing em too far apart, so there aint enough throw in the level (master cylinder) to recover & apply the brakes
Mine are A1 OK now. Gave 'em a good try to the ACE & back today (270mls)

If the pistons are being pushed too far back it's probably the disk which is warped or badly fitted. Put a dial guage on it to check run out when turned.

[kiwiz]

Thanks Guys.

I assume you do this by leaving the wheel in situ and spinning it with a dial gauge up against the disc. Is there any preferred way of mounting the dial gauge?

[Rich]

Usually the brake caliper mounting or fork leg pinch bolts. Needs to have a constant relationship to the disk ie putting the dial guage stand on the floor and spinning the wheel is no good, and be solidly mounted.