classic motorcycle forum

Motorcycle Discussions => Japanese Bikes => Topic started by: madfrank on June 06, 2008, 07:50:52 PM

Title: Kawasaki Z1000 1978
Post by: madfrank on June 06, 2008, 07:50:52 PM
Hiya -

I've got a recurring problem with the back brakes of my Z1000. The pistons don't retract into the calipers and the brakes eventually overheat and jam up. I've had the calipers stripped and cleaned, but the problem comes back. Do I need to re-seal the master cylinder? Is there an anti-return valve in the system? I'd appreciate any advice. I'm no expert. Also where could I find a seal kit.
Thanks in advance.
Frank.
Title: Re: Kawasaki Z1000 1978
Post by: L.A.B. on June 07, 2008, 12:18:43 AM
There definitely should not be any kind of non-return valve in the system, as it is important that any excess fluid pressure can vent back to the master cylinder reservoir when the brake is off.

A common cause of your problem is that the tiny return bleed hole between the master cylinder and the reservoir that allows the pressure to vent back, can block easily, as the hole is normally a very small diameter (less than 1mm). So I would check that is clear, but you will probably have to dismantle the unit first?

Sometimes the inner lining of rubber brake hoses can become detached inside the hose and act as a kind of one-way valve, so if you have a fairly old rubber hose it could be worthwhile replacing it as rubber brake hoses are only supposed to have a maximum life of around 6 to 10 years!
Title: Re: Kawasaki Z1000 1978
Post by: madfrank on June 29, 2008, 01:10:57 AM
Thanks LAB - I'll give that a try. Frank.