83' Kawasaki Z400 j3

Hello,

Basically the front brake is spongy and no matter how many time we go through the process of bleeding them we can't get the required pressure, its like an air bubble is trapped somewhere in the system.

Any ideas gentlemen?



PS sorry If this is the wrong section for this question!

That's a rare bike, at least in the U.S.

When I bleed the front brakes, I take the front calipers off and put them on a table near the same height as the master. Then I put a spacer in place of the pads and disk. By bleeding them this way, you don't have to fight gravity and the bubbles don't get trapped. Make sure the bleed nipples on the calipers are pointing up as they would if installed on the bike.

Also, make sure the master gets bled. This means the master cylinder should be near horizontal. Bubbles will appear at the tiny bleed holes inside the reservoir.

Thanks, thats a good idea (and obvious when you mention it)

Would you happen to know any master cylinders (after market/other brand) that would fit? It may be the case I have to replace mine.

Cheers

If the J3 has a single disc in the front, then you chouls be able to use one from a KZ550A model. If it has dual discs, then you can use a master from a gpz 550 (KZ550D, H, or ZX550A).

The way to tell is to take it apart and see how bad the pitting is inside the master cylinder.

Part ordered, nice one mate!