1.8 Astra conv. Brake problem

[Bob Barker]

Hi, Can anyone help. I have an Astra convertible 1.8 1998. When braking the
pedal sinks, this may be normal but what isnt normel is the ABD cutting in
all the time. I've found a small piece out of the castelated ABS ring on the
CV joint, Is this likely to be the problem?

Thanks

Bob Barker