JCB 520-2 Loadall Year 1982.

Just recently the drivers side front brake has seized. Not sure where the problem lies. The small piston/mechanism behind the foot brake appears to be working so suspect that problem is at the other end. When I open up the bleed valve at the wheel end and let some fluid out this releases the wheel, but when I tighten it up and apply the pedal, the wheel seizes up again. The brake mechanism lies behind a circular plate held on by about 8 12mm bolts. What do you suspect the problem might be? and would it be ok for me to take the plate off to make a further investigation. My knowledge of car disk brakes makes me think that a cylinder or piston of some sort has corroded and is jamming.
Thanks for your time and any light that you can shed on the situation.
Regards
Paul Inman

Paul Inman., September 2011

If there is no free play on the pedal to master cylinder it will lock the oil between the piston and master cylinder free play should be about 1mm

fix-a-jcb, September 2011